Spinal implant distractor/inserter

ABSTRACT

A method for distracting a pair of adjacent vertebrae and inserting an implant within the intervertebral space between the adjacent vertebrae using a posterior angle is described. The method employs a vertebral distractor-inserter comprising a housing, a pair of opposing arms in mechanical communication with the housing, a driving rod extending through at least a portion of the housing and between the arms, wherein the driving rod comprises an axis and a surface with a plurality of angled ratchet teeth on at least a portion of the surface, and a ratchet drive mechanism in mechanical communication with the driving rod.

CROSS-REFERENCE

This application is a continuation-in-part application of Ser. No.11/740,242, filed Apr. 25, 2007, which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION

Spinal disc replacement and/or spinal fusion are sometimes necessary forpatients having lumbar degenerative disc disease. It has been estimatedthat at least 30% of people aged 30 to 50 will have some degree of discspace degeneration, although not all will have pain or ever be diagnosedformally with degenerative disc disease. After a patient reaches 60, itis more normal than not to have some level of disc degeneration. Atwisting injury often starts degenerative disc disease, but it can alsobe initiated by everyday wear and tear on the spine.

Lower back pain is the most common symptom of a compromised discemblematic of degenerative disc disease. For most patients with lumbardegenerative disc disease, the pain is for the most part tolerable andlow-grade, but continuous with occasional flaring of intense pain. Paincan be simply centered on the lower back, or it can radiate to the hipsand legs. It can get worse by sitting, or it can be intensified bytwisting, lifting, or bending. For some, the pain from the diseasedecreases over time, since a fully degenerated disc has no pain-causinginflammatory proteins, and the disc usually collapses into a stableposition-eliminating the micro-motion that often generates the pain.

For many, non-surgical care can successfully treat the symptomsassociated with degenerative disc disease. Doctors will often prescribea regimen of anti-inflammatory medication, pain medication (injected ororal), exercise, physical therapy, and/or chiropractic manipulation. Forothers, however, surgery is the best option for treatment once thenon-surgical care has not resulted in relief and/or the patient's normalactivities have been significantly constrained by his symptoms.

One option for surgical relief is lumbar spinal fusion surgery. Thistreatment stops motion at the painful segment of the spine by fusing twoor more vertebrae. Depending on how many segments of the spine needfusion, and which specific spine segments are to be fused, this surgerymay remove some of the normal motion of the spine. Additionally, wheremultiple segments are fused, back movement may be significantlydiminished, and may itself cause pain (fusion disease). Nevertheless,single-level fusion at the L5-S1 segment, the most likely level to breakdown for degenerative disc disease, for example, does not significantlychange the mechanics in the back and is the most common form of fusion.While lumbar spinal fusion surgery is a major surgery, it can be aneffective option for patients to enhance their activity level andoverall quality of life, particularly when performed using minimallyinvasive techniques. However, while spinal fusion surgery has itsbenefits, and is effective in carefully selected patients, the cost ofthis success is the risk of accelerated degenerative change at adjacentsegments.

Thus, another option to treat lumbar degenerative disc disease throughsurgery is disc replacement using either an artificial disc, a bonegraft from the patient's own iliac crest, or a cadaver bone. Onepotential benefit of disc replacement is the decreased risk of adjacentsegment degeneration. It is postulated that replacing the disc, insteadof fusing adjacent vertebrae together, maintains more of the lumbarspine normal motion, thereby reducing the chance that adjacent levels ofthe spine will break down due to increased stress.

The standard surgical procedure for disc replacement approaches thecervical disc from the front (i.e. anterior approach). The entireworn-out disc is removed. A replacement disc is placed into theintervertebral disc space after the worn-out disc is removed. One goalof this procedure is retention of as much normal motion as possible,while keeping the motion segment stable.

As currently practiced, replacement surgery and spinal fusion from theanterior approach require simultaneous use of multiple tools to keep thespine exposed, to prepare the site for implantation, to distract thevertebrae, and to implant the new disc or graft in the vertebral spaceat the proper orientation and to the desired depth. For example, severaltools are often used to prepare the intervertebral space through removalof the cartilaginous endplates of the vertebral bodies. These tools mayinclude rongeurs, rasps, and curettes. Another tool, such as a sizinggauge, might be used to determine the appropriate position and size ofthe implant to be used. Another tool is used to distract the vertebrae.While this distracting tool is holding the vertebrae apart, yet anothertool may be used to place the implant in the distracted space. In someinstances, a slap-hammer type tool, or an impact-type driver is used toplace the implant between the vertebrae, or to prepare theintervertebral space for the implant.

There is a need for improved tools to aid in disc replacement and/orspinal fusion, which allow a spinal surgeon to more easily access andposition a replacement disc or bone graft within the vertebral space.Additionally there is a need for tools that allow a spinal surgeon tocontrol the implantation depth of a replacement disc or bone graft.There is also a need for a tools that are multifunctional and allow forsingle-handed operation to reduce the number of tools required forperforming multiple functions during disc replacement surgery or duringspinal fusion surgery and to improve the ease and speed with which discreplacement and/or spinal fusion can be completed.

SUMMARY OF THE INVENTION

The foregoing and additional needs are met by embodiments of theinvention, which provide a vertebral distractor-inserter (i.e. device),comprising a pair of opposing arms, a driving rod extending through atleast a portion of the housing and between the pair of opposing arms. Insome embodiments, the driving rod comprises an axis and a surface with aplurality of angled ratchet teeth on at least a portion of the surface,and a ratchet drive mechanism in mechanical communication with thedriving rod. In some embodiments, the vertebral distractor-insertercomprises a housing in mechanical communication with the pair ofopposing arms. In some embodiments, the vertebral distractor-inserter(i.e. device) comprises a handle attached to the housing. The terms“vertebral distractor-inserter,” “distractor-inserter,” and “device” areinterchangeable as used herein.

In some embodiments, the vertebral distractor-inserter comprises aratchet drive mechanism comprising an activating lever mounted to thehousing by an activating lever pivot, a first ratchet pawl coupled tothe activating lever and adapted to engage the ratchet teeth and movethe driving rod distally relative to the housing, and a second ratchetpawl adapted to engage the ratchet teeth and oppose proximal motion ofthe driving rod relative to the housing.

In some embodiments, the vertebral distractor-inserter comprises aratchet drive mechanism comprising an activating lever mounted to thehousing by an activating lever pivot, a first ratchet pawl coupled tothe activating lever and adapted to engage the ratchet teeth and movethe driving rod distally relative to the housing, and an engagingelement to oppose proximal motion of the driving rod relative to thehousing.

In some embodiments the ratchet drive mechanism comprises an activatinglever spring coupled to the activating lever and the handle, wherein theactivating lever spring opposes proximal movement of the lever relativeto the handle. In some embodiments of the distractor-inserter, theratchet drive mechanism comprises a first pawl spring that opposesdownward movement of the first pawl and a second pawl spring thatopposes downward movement of the second pawl.

In some embodiments of the distractor-inserter, the driving rodcomprises a distal end and an implant interface coupled to the distalend of the driving rod.

In some embodiments, the distractor-inserter comprises an implant incontact with the implant interface, whereby distal motion of the drivingrod imparts distal motion to the implant through the implant interface;and distal motion of the implant forces the opposing arms apart.

In some embodiments, each opposing arm comprises an arm pivot. Someembodiments comprise a pair of opposing arms comprising an arm spring.Some embodiments comprise an arm comprising an arm depth guard. In someembodiments, the implant interface comprises an implant coupler.

In some embodiments, the vertebral distractor-inserter is adapted forsingle-handed use.

In some embodiments, the surface of the driving rod comprises an areathat is substantially free of ratchet teeth on a contiguous longitudinalsurface of the driving rod, and the driving rod is movable proximallyrelative to the housing upon rotation of the rod about its axis suchthat the ratchet pawls are in contact with the contiguous longitudinalsurface that is free of ratchet teeth. In some embodiments, the ratchetteeth disengage from first and second ratchet pawls upon rotation of thedriving rod about its axis. In some embodiments, the driving rodcomprises a proximal end having a knob.

Some embodiments of the vertebral distractor-inserter comprise a drivemechanism comprising at least one gripping element which opposesproximal motion of the drive mechanism. The drive mechanism having agripping element may additionally comprise at least one gripping spring.

In some embodiments of the distractor-inserter, the drive mechanismcomprises a gripping element and a ratcheting drive mechanism asdescribed previously. Some embodiments comprise other means for drivingimplant distally. These means can be other mechanical mechanisms capableof imparting unidirectional movement, along with a release mechanism forreversing such unidirectional movement. Some embodiments comprise othermeans for distracting the arms. For example, the arms may be distractedby a built-in distracting member, such as in implant interface adaptedto force the arms apart.

In some embodiments, the vertebral distractor-inserter comprises a pairof opposing arms, a housing in mechanical communication with the pair ofopposing arms and rotatable about an axis extending between the opposingarms, and a driving rod extending through at least a portion of thehousing and between the pair of opposing arms. Some embodiments comprisea distal end having an implant interface, wherein the housing and atleast a portion of the driving rod are rotatable relative to the pair ofopposing arms and the implant interface. Some embodiments furthercomprise an implant interface comprising an interface rotation element,whereby the interface rotation element allows rod rotation relative tothe pair of opposing arms. Some embodiments further comprise a housingcomprising a housing rotation element, whereby the housing rotationelement allows housing and rod rotation relative to the pair of opposingarms.

In some embodiments, the vertebral distractor-inserter comprises a pairof opposing arms, a housing in mechanical communication with the pair ofopposing arms and rotatable about an axis extending between the opposingarms, a driving rod extending through at least a portion of the housingand between the pair of opposing arms, and a drive mechanism adapted tomove the driving rod distally relative to the housing.

In some embodiments of a rotatable vertebral distractor-inserter, thevertebral distractor-inserter comprises a drive mechanism. Embodimentsof the drive mechanism are described herein.

In some embodiments, the invention provides a vertebraldistractor-inserter comprising a housing, a pair of opposing arms inmechanical communication with the housing, a driving rod extendingthrough at least a portion of the housing and between the pair ofopposing arms, a drive mechanism adapted to move the driving roddistally relative to the housing, and an implant depth adjustor that isadjustable to a plurality of implant depth settings and is adapted topush the distractor-inserter proximally upon insertion of an implant toa selected implant depth setting. The implant depth adjustor mayoptionally comprise an implant depth stop. Example drive mechanisms aredescribed herein. This vertebral distractor-inserter may be ratcheting,gripping, a combination of these, etc. Any distractor-inserter describedherein may be adapted for single-handed use. It may also oralternatively comprise an implant interface as described herein. It mayalso be adapted such that the housing and at least a portion of thedriving rod are rotatable about an axis extending between the opposingarms, as described herein.

In some embodiments, the invention provides a method for distractingadjacent vertebrae and inserting an implant between the distractedvertebrae. The method comprises mounting the implant to a driving rod ofa vertebral distractor-inserter having a housing, a pair of opposingarms in mechanical communication with the housing and having a distalend, and a drive mechanism in mechanical communication with the drivingrod, wherein the driving rod extends through at least a portion of thehousing and between the pair of opposing arms. The method furthercomprises positioning the distal end of the pair of arms between thevertebrae, distracting the vertebrae by single-handed operation of thevertebral distractor-inserter, inserting the implant between thedistracted vertebrae by single-handed operation of the vertebraldistractor-inserter, and retracting the pair of opposing arms frombetween the vertebrae.

In some embodiments, the invention further provides a method fordistracting adjacent vertebrae and inserting an implant between thedistracted vertebrae, wherein the distracting comprises activating thedrive mechanism using one hand, and wherein the activating moves theimplant distally and distracts the pair of opposing arms. In someembodiments, insertion comprises advancing the implant into thedistracted space between the vertebrae. In some embodiments advancingthe implant comprises activating the drive mechanism using one hand andextending the implant beyond the distal end of the pair of opposingarms. In some embodiments, the method comprises the additional step ofreleasing the implant from the distractor-inserter.

In some embodiments of the method for distracting adjacent vertebrae andinserting an implant between the distracted vertebrae, the methodcomprises urging the pair of arms between the vertebrae up to theposition where a depth guard of the arms contacts the vertebrae. In someembodiments, the method comprises urging the pair of arms between thevertebrae up to a distal depth of at most about 75 mm, or at least about25 mm, or between about 35 mm and 55 mm. When referring to distal depthherein, “about” refers to variations in depth of between 1 mm and 2 mm,or between 2 mm and 5 mm. In some embodiments, the distal depth is thedistance from the depth guard to the distal end of the pair of opposingarms. In some embodiments, the arms are inserted between the vertebraeup to a distal depth such that the depth guard is proximal to, but notabutting, the proximal side of the vertebrae. In some embodiments, thedepth guard is proximal to and abutting, or contacting, the proximalside of the vertebrae.

In some embodiments, mounting the implant comprises the step ofadjusting the implant depth adjustor to control the maximum implantdepth achievable during the inserting step. In a related embodiment, theimplant depth achievable is a maximum of about 25 mm, a minimum of about0 mm, or between about 3 mm and 8 mm. When referring to implant herein,“about” refers to variations in depth of between 1 mm and 2 mm, orbetween 2 mm and 5 mm. The implant depth is measured from the distal endof the depth stop to the distal end of the implant interface.

In some embodiments insertion of the implant comprises the step ofretracting the pair of opposing arms from between the vertebrae byabutting the implant depth adjustor against a proximal side of thevertebrae and activating the drive mechanism using one hand.

In some embodiments, the invention provides a method comprisingactivating the drive mechanism comprising the step of ratcheting thedriving rod distally. In some such embodiments, the driving rodcomprises an axis and a surface with a plurality of angled ratchet teethon at least a portion of the surface. In some embodiments, the drivemechanism comprises an activating lever capable of movement between afirst position and a second position and mounted to the housing by anactivating lever pivot. In some embodiments, the drive mechanism furthercomprises a first ratchet pawl coupled to the activating lever andadapted to engage the ratchet teeth and move the driving rod distallyrelative to the housing, and a second ratchet pawl adapted to engage theratchet teeth and oppose proximal motion of the driving rod relative tothe housing.

In some embodiments, the invention provides a method comprising grippingthe rod and moving the driving rod distally wherein thedistractor-inserter is an embodiment as described herein. In someembodiments, the step of ratcheting comprises the step of applying aforce to the activating lever to move the lever toward the secondposition. In some embodiments, wherein the drive mechanism comprises ahandle attached to the housing and an activating lever spring coupled tothe activating lever and the handle, and wherein the activating leverspring opposes proximal movement of the lever relative to the handle,the step of ratcheting further comprises the steps of releasing theforce on the activating lever and allowing the activating lever springto move the activating lever toward the first position.

In some embodiments, the invention further provides a method comprisingrotating the housing and at least a portion of the driving rod relativeto the pair of opposing arms and to the implant, wherein the housing isrotatable about an axis extending between the opposing arms relative tothe arms and to the implant, and wherein at least a portion of thedriving rod is rotatable about the axis extending between the opposingarms relative to the pair of opposing arms and to the implant. Thismethod may further comprise activating a drive mechanism wherein theactivating moves the implant distally and distracts the pair of opposingarms. In some embodiments the step of inserting the implant comprisesadvancing the implant into the distracted space between the vertebrae.In some embodiments of the method for distracting adjacent vertebrae andinserting an implant between the distracted vertebrae, the advancingstep comprises activating the drive mechanism and extending the implantbeyond the distal end of the pair of opposing arms.

In some embodiments, the invention provides a method comprising mountingthe implant to a driving rod of a vertebral distractor-inserter having ahousing, a pair of opposing arms, and a ratchet drive mechanism inmechanical communication with the driving rod, wherein the driving rodextends through at least a portion of the housing and between the pairof opposing arms, positioning the distal end of the pair of arms betweenthe vertebrae, distracting the vertebrae, wherein the distractingcomprises activating the ratchet drive mechanism, inserting the implantbetween the distracted vertebrae, wherein the inserting comprisesadvancing the implant into the distracted space between the vertebrae,and wherein the advancing comprises activating the ratchet drivemechanism, and retracting the pair of opposing arms from between thevertebrae.

In some embodiments, the activating step moves the implant distally anddistracts the pair of opposing arms. In some embodiments, advancing theimplant comprises extending the implant beyond the distal end of thepair of opposing arms. In some embodiments, the activating the ratchetdrive mechanism comprises ratcheting the driving rod distally, whereinthe driving rod comprises an axis and a surface with a plurality ofangled ratchet teeth on at least a portion of the surface, and whereinthe ratchet drive mechanism comprises an activating lever capable ofmovement between a first position and a second position and mounted tothe housing by an activating lever pivot, a first ratchet pawl coupledto the activating lever and adapted to engage the ratchet teeth and movethe driving rod distally relative to the housing, and a second ratchetpawl adapted to engage the ratchet teeth and oppose proximal motion ofthe driving rod relative to the housing.

In some embodiments, the invention provides a method comprising a stepof applying a force to the activating lever to move the lever from afirst position toward a second position. In some embodiments the drivemechanism comprises a handle attached to the housing and an activatinglever spring coupled to the activating lever and the handle, wherein theactivating lever spring opposes proximal movement of the lever relativeto the handle. In some embodiments, the step of ratcheting furthercomprises the steps of releasing the force on the activating lever andallowing the activating lever spring to move the activating lever towardthe first position. In some embodiments wherein the implant was coupledto the distractor-inserter, the method comprises releasing the implantfrom the distractor-inserter.

In some embodiments, the invention provides a method comprising mountingthe implant to a driving rod of a vertebral distractor-inserter having apair of opposing arms having a distal end, a housing in mechanicalcommunication with the pair of opposing arms which is rotatable about anaxis extending between the opposing arms relative to the arms and to theimplant, and a drive mechanism in mechanical communication with thedriving rod, wherein the driving rod extends through at least a portionof the housing and between the pair of opposing arms and wherein atleast a portion of the driving rod is rotatable about the axis extendingbetween the opposing arms relative to the pair of opposing arms and tothe implant, positioning the distal end of the pair of arms between thevertebrae, rotating the housing and at least a portion of the drivingrod relative to the pair of opposing arms and to the implant,distracting the vertebrae, inserting the implant between the distractedvertebrae, and retracting the pair of opposing arms from between thevertebrae. The distracting may further comprise activating the drivemechanism, wherein the activating step comprises moving the implantdistally and distracting the pair of opposing arms. Inserting theimplant may comprise advancing the implant into the distracted spacebetween the vertebrae. Advancing the implant may comprise activating thedrive mechanism and extending the implant beyond the distal end of thepair of opposing arms.

The method may further comprise ratcheting the driving rod distally,wherein the driving rod comprises an axis and a surface with a pluralityof angled ratchet teeth on at least a portion of the surface, andwherein the drive mechanism comprises an activating lever capable ofmovement between a first position and a second position and mounted tothe housing by an activating lever pivot, a first ratchet pawl coupledto the activating lever and adapted to engage the ratchet teeth and movethe driving rod distally relative to the housing, and a second ratchetpawl adapted to engage the ratchet teeth and oppose proximal motion ofthe driving rod relative to the housing. The ratcheting can compriseactions previously described herein.

Positioning the implant can further comprise using a depth adjustor tocontrol the implantation depth between the vertebrae. Some embodimentsof the method comprise mounting the implant to a driving rod of avertebral distractor-inserter having a pair of opposing arms having adistal end and a depth guard, an implant depth adjustor that isadjustable to a plurality of implant depth settings, a housing inmechanical communication with the pair of opposing arms, and a drivemechanism in mechanical communication with the driving rod, wherein thedriving rod extends through at least a portion of the housing andbetween the pair of opposing arms, and wherein the mounting comprisesthe step of adjusting the implant depth adjustor to control the maximumdistal implant depth achievable during the inserting step, positioningthe distal end of the pair of arms between the vertebrae, wherein thepositioning comprises urging the pair of arms between the vertebrae upto the position where the depth guard contacts the vertebrae,distracting the vertebrae, inserting the implant between the distractedvertebrae, and retracting the pair of opposing arms from between thevertebrae.

In some embodiments, the invention provides a method comprising urgingthe pair of arms between the vertebrae. The step of urging is capable ofmoving the pair of arms between the vertebrae up to a distal depth of atmost about 75 mm, or at least about 25 mm, or between about 35 mm and 55mm. When referring to distal depth herein, “about” refers to variationsin depth of between 1 mm and 2 mm, or between 2 mm and 5 mm. In someembodiments, the distal depth is the distance from the depth guard tothe distal end of the pair of opposing arms. In some embodiments, thearms are inserted between the vertebrae up to a distal depth such thatthe depth guard is proximal to, but not abutting, the proximal side ofthe vertebrae. In some embodiments, the depth guard is proximal to andabutting, or contacting, the proximal side of the vertebrae.

In some embodiments, the implant depth achievable is a maximum of about25 mm, a minimum of about 0 mm, or between about 3 mm and 8 mm. Whenreferring to implant herein, “about” refers to variations in depth ofbetween 1 mm and 2 mm, or between 2 mm and 5 mm. The implant depth ismeasured from the distal end of the depth stop to the distal end of theimplant interface.

In some embodiments, the distractor-inserter has a housing and isadapted to push the housing proximally upon insertion of the implant toa selected implant depth setting, and the inserting comprises the stepof retracting the pair of opposing arms from between the vertebrae byabutting the arm depth guard against a proximal side of the vertebraeand activating the drive mechanism.

In some embodiments, the invention provides a vertebraldistractor-inserter, comprising a housing, a pair of opposing arms inmechanical communication with the housing, and a driving means fordriving a rod and an implant at the distal end of the rod distally,wherein the driving means comprises an activating lever and a drivingmechanism activated by the activating lever. The driving means maycomprise a gripping means for gripping the rod while the activatinglever drives the rod distally relative to the housing. The driving meansmay comprise a ratcheting means for incrementally ratcheting the roddistally as the activating lever is pulled proximally relative to thehousing. The vertebral distractor-inserter may comprise a holding meansfor opposing proximal motion of the rod while resetting the lever afterlever activation. The vertebral distractor-inserter may comprise arotating means for allowing operator rotation of the housing relative tothe pair of opposing arms about an axis extending between the opposingarms. The vertebral distractor-inserter may comprise a depth-controllingmeans for adjusting and controlling the depth to which an implant may beinserted by an operator between adjacent vertebrae.

Provided herein are a variety of methods for distracting adjacentvertebrae and for inserting an implant into the intervertebral space.One method includes a method of inserting a spinal implant between twovertebrae, comprising: (a) placing an intervertebral implant between apair of opposing arms of a vertebral distractor-inserter, thedistractor-inserted comprising: (i) the pair of opposing arms, havingdistal ends; (ii) a driving rod extending between the pair of opposingarms, wherein the driving rod comprises an axis and a surface with aplurality of angled ratchet teeth on at least a portion of the surface;and (iii) a drive mechanism in mechanical communication with the drivingrod; (b) inserting said distal ends of the pair of opposing arms betweena pair of vertebrae from a posterior angle; and (c) actuating saiddistractor-inserter, thereby distracting said vertebrae and insertingsaid implant between said vertebrae. In some embodiments, the methodfurther provides for a device wherein the driving rod comprises an axisand a surface having a plurality of angled ratchet teeth on at least aportion of the surface. The method can further comprise a ratchet drivemechanism in communication with the angled ratchet teeth. Alternatively,the method can comprise the use of a device comprising a screw drivemechanism. The device can be introduced between the pair of vertebraefrom a posterior angle, where the posterior angle is generally parallelto the axial plane and sagittal plane. In some embodiments of themethod, the device can be introduced between the pair of vertebrae froma posterior angle where the posterior angle is substantially parallel tothe axial plane but deviates about 20 to about 60 degrees with respectto the sagittal plane. The method further comprises the use of adistractor-inserter for inserting a spinal implant between thevertebrae. In some embodiments, the implant has laterally opposing wallsthat are substantially parallel to the axis of insertion. The method canfurther comprise inserting at least two implants into the intervertebralspace. One implant can be inserted on one side of the spinous processand another implant can be inserted on the other side of the spinousprocess. In some embodiments, the implant has laterally opposing wallsthat are substantially curved. In some embodiments of the method, one ofthe opposing walls is substantially parallel to the axis of insertionand the other opposing wall is substantially curved. In some embodimentsof the method, the actuating step can further comprise inserting animplant having laterally opposing walls in the intervertebral spacewherein the inserting of the implant comprises repositioning the implantin the intervertebral space by following the curvature of the implant.The method can further comprise the use of a distractor-inserter inwhich the distractor-inserter comprises a housing in mechanicalcommunication with the pair of opposing arms, wherein the driving rodextends through at least a portion of the housing. Thedistractor-inserter can comprise a handle attached to the housing.Additionally, the method for inserting a spinal implant between twovertebrae can comprise the use of a ratchet drive mechanism, wherein theratchet drive mechanism of the distractor-inserter comprises: (a) anactivating lever mounted to the housing by an activating lever pivot;(b) a first ratchet pawl coupled to the activating lever and adapted toengage the ratchet teeth and move the driving rod distally relative tothe housing; and (c) a second ratchet pawl adapted to engage the ratchetteeth and oppose proximal motion of the driving rod relative to thehousing. Furthermore, the method can comprise the use of adistractor-inserter can comprise a handle attached to the housing andthe ratchet drive mechanism comprises an activating lever spring coupledto the activating lever and the handle, wherein the activating leverspring opposes proximal movement of the lever relative to the handle. Insome embodiments of the method, the ratchet-drive mechanism comprises:(a) a first pawl spring that opposes downward movement of the firstpawl; and (b) a second pawl spring that opposes downward movement of thesecond pawl. The surface of the driving rod comprises an area that issubstantially free of ratchet teeth on a contiguous longitudinal surfaceof the driving rod, and wherein the driving rod is movable proximallyrelative to the housing upon rotation of the rod about its axis suchthat the ratchet pawls are in contact with the contiguous longitudinalsurface that is free of ratchet teeth. The ratchet teeth can disengagefrom the first and second ratchet pawls upon rotation of the driving rodabout its axis.

Additionally provided herein is a method of inserting a spinal implantbetween two vertebrae, comprising: (a) placing an intervertebral implantbetween a pair of opposing arms of a vertebral distractor-inserter, thedistractor-inserted comprising: (i) a pair of opposing arms havingdistal ends; (ii) a housing in mechanical communication with the pair ofopposing arms and rotatable about an axis extending between the opposingarms; and (iii) a driving rod extending through at least a portion ofthe housing and between the pair of opposing arms; (b) inserting saiddistal ends of the pair of opposing arms between a pair of vertebraefrom a posterior angle; and (c) actuating said distractor-inserter,thereby distracting said vertebrae and inserting said implant betweensaid vertebrae. The method can further provide for the use of adistractor-inserter wherein the driving rod comprises a distal endhaving an implant interface, wherein the housing and at least a portionof the driving rod are rotatable relative to the pair of opposing armsand the implant interface. The implant interface can additionallycomprises an interface rotation element, whereby the interface rotationelement allows rod rotation relative to the pair of opposing arms. Thehousing can comprises a housing rotation element, whereby the housingrotation element allows housing and rod rotation relative to the pair ofopposing arms. In some embodiments, the distractor-inserter is adaptedfor single-handed use. The method can further provide for a device thatcan be introduced between the pair of vertebrae from a posterior angle,where the posterior angle is generally parallel to the axial plane andsagittal plane. In some embodiments of the method, the device can beintroduced between the pair of vertebrae from a posterior angle wherethe posterior angle is substantially parallel with respect to the axialplane but deviates about 20 to about 60 degrees with respect to thesagittal plane. The method further comprises the use of adistractor-inserter for inserting a spinal implant between thevertebrae. In some embodiments, the implant has laterally opposing wallsthat are substantially parallel to the axis of insertion. The method canfurther comprise inserting at least two implants into the intervertebralspace. One implant can be inserted on one side of the spinous processand another implant can be inserted on the other side of the spinousprocess. In some embodiments of the method, the implant has laterallyopposing walls that are substantially curved. In some embodiments, oneof the opposing walls is substantially parallel to the axis of insertionand the other opposing wall is substantially curved. In some embodimentsof the method, the actuating step can further comprise inserting animplant having laterally opposing walls in the intervertebral spacewherein the inserting of the implant comprises repositioning the implantin the intervertebral space by following the curvature of the implant.

Further provided herein is a method of inserting an implant betweenvertebrae, comprising: (a) placing a vertebral implant between a pair ofopposing arms of a vertebral distractor-inserter, saiddistractor-inserter comprising: (i) a housing; (ii) a pair of opposingarms in mechanical communication with the housing; (iii) a driving rodextending through at least a portion of the housing and between the pairof opposing arms; and (iv) a drive mechanism in mechanical communicationwith the driving rod, wherein the drive mechanism is adapted to move thedriving rod distally relative to the housing, and wherein thedistractor-inserter is adapted for single-handed distraction ofvertebrae and insertion of a vertebral implant; (b) inserting saiddistal ends of the pair of opposing arms between a pair of vertebraefrom a posterior angle; and actuating said distractor-inserter, therebydistracting said vertebrae and inserting said implant between saidvertebrae. The method can further provide for a device that can beintroduced between the pair of vertebrae from a posterior angle, wherethe posterior angle is generally parallel to the axial plane andsagittal plane. In some embodiments of the method, the device can beintroduced between the pair of vertebrae from a posterior angle wherethe device is introduced at a posterior angle that is substantiallyparallel to the axial plane but which deviates about 20 to about 60degrees with respect to the sagittal plane. The method further comprisesthe use of a distractor-inserter for inserting a spinal implant betweenthe vertebrae. In some embodiments, the implant has laterally opposingwalls that are substantially parallel to the axis of insertion. Themethod can further comprise inserting at least two implants into theintervertebral space. One implant can be inserted on one side of thespinous process and another implant can be inserted on the other side ofthe spinous process. In some embodiments, the implant has laterallyopposing walls that are substantially curved. In some embodiments, oneof the opposing walls is substantially parallel to the axis of insertionand the other opposing wall is substantially curved. In some embodimentsof the method, the actuating step can further comprise inserting animplant having laterally opposing walls in the intervertebral spacewherein the inserting of the implant comprises repositioning the implantin the intervertebral space by following the curvature of the implant.

Another method provided herein is a method for distracting adjacentvertebrae and inserting an implant between the distracted vertebrae froma posterior angle, comprising: (a) mounting the implant to a driving rodof a vertebral distractor-inserter having a pair of opposing arms, adistal end, and a drive mechanism in mechanical communication with thedriving rod, wherein the driving rod extends between the pair ofopposing arms; (b) positioning the distal end of the pair of armsbetween the vertebrae from a posterior angle; (c) distracting thevertebrae by single-handed operation of the vertebraldistractor-inserter; (d) inserting the implant between the distractedvertebrae by single-handed operation of the vertebraldistractor-inserter; and (e) retracting the pair of opposing arms frombetween the vertebrae. The distracting step can further compriseactivating the drive mechanism using one hand, wherein the activatingmoves the implant distally and distracts the pair of opposing arms. Insome embodiments of the method, the vertebral distractor-inserter has ahousing in mechanical communication with the pair of opposing arms,wherein the driving rod extends through at least a portion of thehousing. Additionally, the inserting step of the method for distractingadjacent vertebrae can further comprise advancing the implant into thedistracted space between the vertebrae. The advancing step can compriseactivating the drive mechanism using one hand and extending the implantbeyond the distal end of the pair of opposing arms. In some embodiments,the method further comprises the additional step of releasing theimplant from the distractor-inserter. The method provided can includethe use of a distractor-inserter comprising a the pair of opposing armscomprising a depth guard, and wherein the positioning step comprisesurging the pair of arms between the vertebrae up to the position wherethe depth guard contacts the vertebrae. In some embodiments of themethod, the vertebral distractor-inserter has a housing in mechanicalcommunication with the pair of opposing arms, wherein the driving rodextends through at least a portion of the housing, and wherein theactivating the drive mechanism comprises the step of ratcheting thedriving rod distally, wherein the driving rod comprises: (a) an axis and(b) a surface with a plurality of angled ratchet teeth on at least aportion of the surface, and wherein the drive mechanism comprises: (i)an activating lever capable of movement between a first position and asecond position and mounted to the housing by an activating lever pivot,(ii) a first ratchet pawl coupled to the activating lever and adapted toengage the ratchet teeth and move the driving rod distally relative tothe housing, and (iii) a second ratchet pawl adapted to engage theratchet teeth and oppose proximal motion of the driving rod relative tothe housing. The method can further provide for a device that can beintroduced between the pair of vertebrae from a posterior angle, wherethe posterior angle is generally parallel to the axial and sagittalplane. In some embodiments of the method, the device can be introducedbetween the pair of vertebrae from a posterior angle where the posteriorangle is substantially parallel to the axial plane but deviates about 20to about 60 degrees with respect to the sagittal plane. The methodfurther comprises the use of a distractor-inserter for inserting aspinal implant between the vertebrae. In some embodiments, the implanthas laterally opposing walls that are substantially parallel to the axisof insertion. The method can further comprise inserting at least twoimplants into the intervertebral space. One implant can be inserted onone side of the spinous process and another implant can be inserted onthe other side of the spinous process. In some embodiments, the implanthas laterally opposing walls that are substantially curved. In someembodiments, one of the opposing walls is substantially parallel to theaxis of insertion and the other opposing wall is substantially curved.In some embodiments of the method, the actuating step can furthercomprise inserting an implant having laterally opposing walls in theintervertebral space wherein the inserting of the implant comprisesrepositioning the implant in the intervertebral space by following thecurvature of the implant.

In some embodiments, further provided is a method for distractingadjacent vertebrae and inserting an implant between the distractedvertebrae from a posterior angle, comprising the steps of: (a) mountingthe implant to a driving rod of a vertebral distractor-inserter having apair of opposing arms, and a ratchet drive mechanism in mechanicalcommunication with the driving rod, wherein the driving rod extendsbetween the pair of opposing arms; (b) positioning the distal end of thepair of arms between the vertebrae from a posterior angle; (c)distracting the vertebrae, wherein the distracting comprises activatingthe ratchet drive mechanism; (d) inserting the implant between thedistracted vertebrae, wherein the inserting comprises advancing theimplant into the distracted space between the vertebrae, and wherein theadvancing comprises activating the ratchet drive mechanism; and (e)retracting the pair of opposing arms from between the vertebrae. Theactivating step can further comprise moving the implant distally anddistracting the pair of opposing arms. The step of activating theratchet drive mechanism, in some embodiments, can further comprise thestep of ratcheting the driving rod distally, wherein the driving rodcomprises: (a) an axis; and (b) a surface with a plurality of angledratchet teeth on at least a portion of the surface, and wherein theratchet drive mechanism comprises: (i) an activating lever capable ofmovement between a first position and a second position and mounted tothe housing by an activating lever pivot, (ii) a first ratchet pawlcoupled to the activating lever and adapted to engage the ratchet teethand move the driving rod distally relative to the housing, and (iii) asecond ratchet pawl adapted to engage the ratchet teeth and opposeproximal motion of the driving rod relative to the housing. The devicecan be introduced between the pair of vertebrae from a posterior angle,where the posterior angle is generally parallel to the axial andsagittal planes. In some embodiments of the method, the device can beintroduced between the pair of vertebrae from a posterior angle wherethe posterior angle is substantially parallel with respect to the axialplane but which deviates about 20 to about 60 degrees with respect tothe sagittal plane. The method further comprises the use of adistractor-inserter for inserting a spinal implant between thevertebrae. In some embodiments, the implant has laterally opposing wallsthat are substantially parallel to the axis of insertion. The method canfurther comprise inserting at least two implants into the intervertebralspace. One implant can be inserted on one side of the spinous processand another implant can be inserted on the other side of the spinousprocess. In some embodiments, the implant has laterally opposing wallsthat are substantially curved. In some embodiments, one of the opposingwalls is substantially parallel to the axis of insertion and the otheropposing wall is substantially curved. In some embodiments of themethod, the actuating step can further comprise inserting an implanthaving laterally opposing walls in the intervertebral space wherein theinserting of the implant comprises repositioning the implant in theintervertebral space by following the curvature of the implant.

Yet another embodiment of the method provided herein includes a methodfor distracting adjacent vertebrae and inserting an implant between thedistracted vertebrae from a posterior angle, comprising the steps of:(a) mounting the implant to a driving rod of a vertebraldistractor-inserter having: (i) a pair of opposing arms having a distalend, (ii) a housing in mechanical communication with the pair ofopposing arms which is rotatable about an axis extending between theopposing arms relative to the arms and to the implant, and (iii) a drivemechanism in mechanical communication with the driving rod, wherein thedriving rod extends through at least a portion of the housing andbetween the pair of opposing arms and wherein at least a portion of thedriving rod is rotatable about the axis extending between the opposingarms relative to the pair of opposing arms and to the implant; (b)positioning the distal end of the pair of arms between the vertebraefrom a posterior angle; (c) rotating the housing and at least a portionof the driving rod relative to the pair of opposing arms and to theimplant; (d) distracting the vertebrae; (e) inserting the implantbetween the distracted vertebrae; and (f) retracting the pair ofopposing arms from between the vertebrae. The distracting step canfurther comprise activating the drive mechanism, wherein the activatingmoves the implant distally and distracts the pair of opposing arms.Additionally, the inserting step of the method can further compriseadvancing the implant into the distracted space between the vertebrae.The device can be introduced between the pair of vertebrae from aposterior angle, where the posterior angle is generally parallel to theaxial plane and sagittal plane. In some embodiments of the method, thedevice can be introduced between the pair of vertebrae from a posteriorangle where the posterior angle is substantially parallel to the axialplane but deviates about 20 to about 60 degrees with respect to thesagittal plane. The method further comprises the use of adistractor-inserter for inserting a spinal implant between thevertebrae. In some embodiments, the implant has laterally opposing wallsthat are substantially parallel to the axis of insertion. The method canfurther comprise inserting at least two implants into the intervertebralspace. One implant can be inserted on one side of the spinous processand another implant can be inserted on the other side of the spinousprocess. In some embodiments, the implant has laterally opposing wallsthat are substantially curved. In some embodiments, one of the opposingwalls is substantially parallel to the axis of insertion and the otheropposing wall is substantially curved. In some embodiments of themethod, the actuating step can further comprise inserting an implanthaving laterally opposing walls in the intervertebral space wherein theinserting of the implant comprises repositioning the implant in theintervertebral space by following the curvature of the implant.

Another embodiment of the method provided herein comprises a method fordistracting adjacent vertebrae and inserting an implant between thedistracted vertebrae from a posterior angle, comprising the steps of:(a) mounting the implant to a driving rod of a vertebraldistractor-inserter having (i) a pair of opposing arms having a distalend and a depth guard, (ii) an implant depth adjustor that is adjustableto a plurality of implant depth settings, (iii) a housing in mechanicalcommunication with the pair of opposing arms, and (iv) a drive mechanismin mechanical communication with the driving rod, wherein the drivingrod extends through at least a portion of the housing and between thepair of opposing arms, wherein the mounting comprises the step ofadjusting the implant depth adjustor to control the maximum distalimplant depth achievable during the inserting step; (b) positioning thedistal end of the pair of arms between the vertebrae, wherein thepositioning comprises urging the pair of arms between the vertebrae upto the position where the depth guard contacts the vertebrae; (c)distracting the vertebrae; (d) inserting the implant between thedistracted vertebrae from a posterior angle; and (e) retracting the pairof opposing arms from between the vertebrae. The device can beintroduced between the pair of vertebrae from a posterior angle, wherethe posterior angle is generally parallel to the axial plane andsagittal plane. In some embodiments of the method, the device can beintroduced between the pair of vertebrae from a posterior angle wherethe posterior angle is substantially parallel to the axial plane butdeviates about 20 to about 60 degrees with respect to the sagittalplane. The method further comprises the use of a distractor-inserter forinserting a spinal implant between the vertebrae. In some embodiments,the implant has laterally opposing walls that are substantially parallelto the axis of insertion. The method can further comprise inserting atleast two implants into the intervertebral space. One implant can beinserted on one side of the spinous process and another implant can beinserted on the other side of the spinous process. In some embodiments,the implant has laterally opposing walls that are substantially curved.In some embodiments, one of the opposing walls is substantially parallelto the axis of insertion and the other opposing wall is substantiallycurved. In some embodiments of the method, the actuating step canfurther comprise inserting an implant having laterally opposing walls inthe intervertebral space wherein the inserting of the implant comprisesrepositioning the implant in the intervertebral space by following thecurvature of the implant.

Further provided herein is a method of implanting an implant in anintervertebral space comprising: (a) providing a distractor-insertercomprising (i) a pair of opposing arms, having distal ends; (ii) adriving rod extending between the pair of opposing arms; and (iii) adrive mechanism in mechanical communication with the driving rod; (b)inserting the distal end of the pair of arms between the vertebrae froma posterior angle; (c) actuating the distractor-inserter, therebydistracting said vertebrae and inserting said implant between saidvertebrae; and (d) repositioning said implant so that it occupies ananterior vertebral space. The method further comprises inserting animplant that has laterally opposing walls that are substantially curvedwith respect to the axis of insertion. The method can further compriseinsertion of an implant from a posterior angle, where the posteriorangle is generally parallel to the axial plane and sagittal plane. Insome embodiments of the method, the device can be introduced between thepair of vertebrae from a posterior angle where the posterior angle issubstantially parallel to the axial plane but which deviates about 20 toabout 60 degrees with respect to the sagittal plane. The method furthercomprises the use of a distractor-inserter for inserting a spinalimplant between the vertebrae.

Yet another method provided herein is a method of implanting implantsinto an intervertebral space comprising: (a) providing adistractor-inserter comprising (i) a pair of opposing arms, havingdistal ends; (ii) a driving rod extending between the pair of opposingarms; and (iii) a drive mechanism in mechanical communication with thedriving rod; (b) inserting the distal end of the pair of arms betweenthe vertebrae from a posterior angle; (c) actuating thedistractor-inserter, thereby distracting said vertebrae and insertingsaid implant between said vertebrae; and (d) repeating steps (a)-(c) onthe contralateral side of the spinous process. In some embodiments, theimplant has laterally opposing walls that are substantially parallel tothe axis of insertion. The implant can be boxed-shaped. The method canfurther comprise inserting at least two implants into the intervertebralspace. One implant can be inserted on one side of the spinous processand another implant can be inserted on the contralateral side of thespinous process. In some embodiments, the posterior angle issubstantially parallel to the axial plane and the sagittal plane. Insome embodiments of the method, the device can be introduced between thepair of vertebrae from a posterior angle where the posterior angle isparallel to the axial plane but which deviates about 20 to about 60degrees with respect to the sagittal plane.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1A: Depicts a lateral view of the spinal column.

FIG. 1B: Depicts a perspective view of the anatomical planes of thehuman body.

FIGS. 2A & 2B: Depict external views of an embodiment of a deviceaccording to the present invention.

FIG. 2C: Provides a top view of an embodiment of a device according tothe present invention.

FIG. 3A: Shows a cutaway side view of an embodiment of the device havingratchet teeth engaged.

FIG. 3B: Shows a cutaway side view of the housing of an embodiment ofthe device having ratchet teeth engaged by the drive mechanism whereinthe activating lever is in a first position.

FIG. 3C: Shows a cutaway side view of the housing of an embodiment ofthe device having ratchet teeth engaged by the drive mechanism whereinthe activating lever is in a second position.

FIG. 4A: Provides a cutaway side view of an embodiment of the devicehaving ratchet teeth disengaged for retraction of the driving rod.

FIG. 4B: Provides a cutaway side view the housing of an embodiment ofthe device having ratchet teeth disengaged for retraction of the drivingrod.

FIG. 5A: Depicts a non-ratcheting embodiment of the device.

FIG. 5B: Shows a cutaway side view of the housing of a non-ratchetingembodiment of the device.

FIGS. 6A & 6B: Depict views of an embodiment of the device showingrelative rotation of the arms and the handle.

FIGS. 7A & 7B: Depict views of an embodiment of the device showing animplant depth adjustment feature.

FIG. 8: Shows a view of an embodiment of the device in use. In thisview, the vertebrae are distracted to permit insertion of an implant.

FIG. 9: Shows a view of an embodiment of the device in use. In thisview, an intervertebral implant is inserted between the distractedvertebrae, wherein the arms have been retracted from the space betweenthe vertebrae.

FIGS. 10A-10C: Depict external views of an embodiment of a deviceaccording to the present invention.

FIG. 10D: Provides a top view of an embodiment of a device according tothe present invention.

FIG. 11A: Shows a view of an embodiment of the device in use where thedevice accesses the intervertebral space using a posterior-lateralapproach.

FIG. 11B: illustrates a close up view of the device in use in FIG. 11Awhere one embodiment of an implant has been inserted into theintervertebral space using a posterior-lateral approach.

FIGS. 12A-12F: illustrate various embodiments of an implant.

FIG. 13A: Shows another view of an embodiment of the device in use wherethe device accesses the intervertebral space using a direct posteriorapproach.

FIG. 13B: Shows a close up view of the device in use in FIG. 13A whereanother embodiment of an implant has been inserted into theintervertebral space using a direct posterior approach.

FIGS. 14A-14F: illustrate various embodiments of another implant.

FIG. 15: Shows another view of an embodiment of the device in use wherethe device accesses the intervertebral space using a posterior-lateralapproach. The device is shown accessing the posterior side of the spinalcord at an angle.

DETAILED DESCRIPTION OF THE INVENTION

The invention disclosed herein provides a tool to aid in intervertebraldisc replacement and/or spinal fusion. The tool, i.e. device, allows aspinal surgeon to more easily access and position a replacement disc orgraft within the vertebral space. In some embodiments, the device allowsa spinal surgeon to control implantation depth of a replacement disc orgraft. Additionally disclosed is a multifunctional device that permitssubstantially single-handed operation. Such a device reduces the numberof tools required for performing multiple functions during discreplacement surgery and/or spinal fusion surgery, while freeing up anoperator's other hand. In some embodiments, the tool, i.e. device, isrotatable about an axis extending between a pair of opposed arms. Suchembodiments provide improved ergonomics and ease of use during the discreplacement surgery and/or spinal fusion surgery. By providing one ormore of the preceding advantages, the device described herein improvesthe ease and speed with which disc replacement or spinal fusion surgerycan be completed using an anterior lumbar angle. The terms “vertebraldistractor-inserter,” “distractor-inserter,” and “device” areinterchangeable as used herein.

The invention will now be further described with reference to theappended drawings, which are intended to be illustrative of certainpreferred embodiments of the invention, but are not intended to limitthe scope of the invention. One of skill in the art will recognize thatother embodiments of the invention are possible within the scope of theinvention; and no disclaimer of such additional embodiments is intendedby referring to the illustrative examples.

The spinal cord is a collection of neurons that travels within thevertebral column and is an extension of the central nervous system. Thespinal cord extends from the brain and is enclosed in and protected bythe bony vertebral column. A body cavity 5 with spinal column is shownin FIG. 1A. The devices of the invention are designed to interact withthe human spinal column 10, as shown in FIG. 1A, which is comprises of aseries of thirty-three stacked vertebrae 12 divided into five regions.The cervical region includes seven vertebrae, known as C1-C7. Thethoracic region includes twelve vertebrae, known as T1-T12. The lumbarregion contains five vertebrae, known as L1-L5. The sacral region iscomprised of five fused vertebrae, known as S1-S5, while the coccygealregion contains four fused vertebrae, known as Co1-Co4.

In order to understand the configurability, adaptability, andoperational aspects of the invention, it is helpful to understand theanatomical references of the body 50 with respect to which the positionand operation of the devices and components thereof, are described.There are three anatomical planes generally used in anatomy to describethe human body and structure within the human body; the axial plane 52,the sagittal plane 54 and the coronal plane 56 (see FIG. 1B).Additionally, devices and the operation of devices are better understoodwith respect to the caudal 60 direction and/or the cephalad direction62. Devices positioned within the body can be positioned dorsally 70 (orposteriorly) such that the placement or operation of the device istoward the back or rear of the body. Alternatively, devices can bepositioned ventrally 72 (or anteriorly) such that the placement oroperation of the device is toward the front of the body. Variousembodiments of the spinal devices and systems of the present inventionmay be configurable and variable with respect to a single anatomicalplane or with respect to two or more anatomical planes. For example, acomponent may be described as lying within and having adaptability oroperability in relation to a single plane. For example, a stem may bepositioned in a desired location relative to an axial plane and may bemoveable between a number of adaptable positions or within a range ofpositions. Similarly, the various components can incorporate differingsizes and/or shapes in order to accommodate differing patient sizesand/or anticipated loads. The device may be used in any individual forwhom use of the device is suitable, including any animal belonging tothe mammalia class, such as warm-blooded, vertebrate animals.

FIGS. 2A, 2B, and 2C depict external views of one currently preferredembodiment of the device 168. FIG. 2A depicts an embodiment of avertebral distractor-inserter 168 comprising a housing 136, a pair ofopposing arms 152A, 152B in mechanical communication with the housing136, a driving rod 126 extending through at least a portion of thehousing 136 and between the pair of opposing arms 152A, 152B, whereinthe driving rod 126 comprises an axis 118 and a surface 166 with aplurality of angled ratchet teeth 110 on at least a portion of thesurface 166, and a ratchet drive mechanism in mechanical communicationwith the driving rod 126. In some embodiments, the vertebraldistractor-inserter 168 comprises a handle 128 attached to the housing136. In some embodiments, the vertebral distractor-inserter 168 does notcomprise a housing 136. In some embodiments, the housing 136 does notenclose the rod 126. In some embodiments, the rod 126 is external to,but in communication with, the housing 136.

FIG. 2A further depicts an embodiment having an activating lever 102,which is in mechanical communication with the driving rod 126. Movementof the activating lever 102 in the direction of the handle 128 causesthe driving rod 126 and an implant (not shown) at the distal end of thedriving rod 126 to move distally relative to the housing 136. Themechanical communication may be effected through a number of means; inthe depicted embodiment the mechanical communication is through aratcheting drive mechanism 124 within the housing 136. The ratchetingdrive mechanism 124 uses ratchet teeth 110 to grip the driving rod 126and drive the implant and the rod 126 distally when the activating lever102 is moved toward the handle 128.

The embodiment shown has an implant coupler 140 and an implant depthadjustor 142. The implant coupler 140 abuts the implant and transfersforce from the driving rod 126 to the implant, which in turn forces thelower arm 152B and the upper arm 152A apart, providing distractingforce. The implant depth adjustor controls the depth to which an implantcan be implanted when the depth stop 146 contacts the vertebra (notshown) during insertion. The embodiment has an arm depth guard 112,which determines the maximum depth to which the arms 152A, 152B can beinserted between the vertebrae during distraction. In the embodimentshown in FIG. 2A, the driving rod 126 is fully retracted and the distalend of the arms 152A, 152B are ready for insertion between the vertebraefor subsequent distraction and implant insertion.

FIG. 2B shows a similar embodiment of the device 168 in the fullyextended position, wherein the implant coupler 140, depth stop 146 anddepth adjustor 142 are at their most distal position. This view showswhat the device 168 would look like after use of the device 168 todistract the vertebrae and after insertion of the implant. This figurealso shows an arm pivot 114, about which the arms 152A, 152B may pivotto distract the vertebrae upon distal movement of the implant and theimplant coupler 140, the implant depth adjustor 142, and the implantdepth stop 146.

FIG. 2C depicts a top view of an embodiment of the device 168 with theimplant coupler 140, depth stop 146, and adjustor 142 in an intermediateposition between full retraction and full extension. In this view, thehousing 136 is shown along with the driving rod 126, which extendsthrough the housing 136. Also visible is the implant depth stop 146,which travels in a groove 182 of the arm 152A. This view also shows aknob 150 on the proximal end of the driving rod 126, discussed furtherbelow.

FIG. 3A shows a cutaway side view of an embodiment of the device 268having ratchet teeth 210 engaged. Further shown is a first ratchet pawl232 and a first pawl spring 230 which work together with the activatinglever 202, activating lever spring 206 and activating lever pivot 204 todrive the driving rod 226 distally when the activating lever 202 ismoved toward the handle 228 (i.e. toward a second position from a firstposition, shown by the double-headed arrow of FIG. 3A). When an operatorgrips the handle and the activating lever 202 in one hand and pulls theactivating lever 202 proximally toward the handle 228, the activatinglever 202 moves the first ratchet pawl 232 distally by pivoting aboutthe activating lever pivot 204. Since the first ratchet pawl 232 isengaged against the ratchet teeth 210 of the driving rod 226, the distalmotion of the ratchet pawl 232 drives the driving rod 226 distally. Alsodepicted in this view is a second ratchet pawl 260 and a second pawlspring 258. The second ratchet pawl 260 cannot move distally orproximally, but the second ratchet spring 258 allows the second pawl tomove away from the driving rod 226 as each angled ratchet tooth 210advances distally. Once each tooth 210 passes the second pawl 260, thepawl spring 258 pushes the second pawl 260 back toward the driving rod226, to engage the next ratchet tooth 210 along the driving rod 226.Thus the second ratchet pawl 260 allows distal motion of the arm 226 andprevents proximal motion of the arm 226. As the activating lever 202 ispulled again or farther toward the handle 228, further distal motion isimparted to the arm 226.

Thus, the second ratchet pawl 260 and the second pawl spring 258cooperate to restrict or oppose proximal motion of the driving rod 226as the activating lever 202 is reset away from the handle 228. In thedepicted embodiment, the activating lever 202 has a spring 206 whichbiases the lever 202 toward the first position. Once the operatorreleases the force on the lever 202, the activating lever spring 206moves the lever 202 away from the handle 228 toward its originalposition. As this occurs, the first pawl 232 and first pawl spring 230,linked to the activating lever 202, are also returned toward theiroriginal positions relative to the housing 236 prior to the operatorpulling the lever 202 proximally. This occurs with no distal or proximalmotion of the driving rod 226 since the first pawl spring 230 allows thefirst pawl 232 to move away and toward the driving rod 226 along theratchet teeth 210 of the rod 226 as the pawl 232 ramps along the teeth210 proximally. The second ratchet pawl 260, engaged against the ratchetteeth 210, opposes proximal motion of the rod 226 during this action. Inembodiments where a gripping or other type of driving mechanism is used,the second ratcheting pawl 260 and spring 258 may be used to providesimilar restricted proximal motion where the driving rod 226 comprisessome ratchet teeth 210 on at least a portion of the rod 226 which cancooperate with the second ratchet pawl 260 and spring 258. It is to beunderstood that the spring 206 may be eliminated in some embodiments andstill provide substantially single handed operation. In such cases, theactivating lever 202 will have to be moved toward the first positionmanually. This can be facilitated by including a closed handle (loop)similar to those common on scissors and forceps at the lower end of theactivating lever 202, through which an operator may place her fingersand by means of which an operator can impart force to the lever 202 ineither the direction away from or toward the handle 228 with a singlehand.

In another embodiment, the device comprises a holding means wherein asecond ratchet pawl and second ratchet spring are not present. Theholding means instead may comprise, for example, a pneumatic grip, ahook, a latch, a grabbing device, the gripping mechanism describedfurther herein, manually holding the driving rod in its distal position,or another mechanical means of restricting proximal motion.

In other embodiments, the device comprises a driving means comprising afirst ratchet pawl and a spring that engages a thread which winds aroundthe driving rod. Ratchet teeth may be unnecessary in this embodiment.The activating lever may instead drive the driving rod and implantdistally by engaging the threads in the same ratcheting manner describedherein, and retraction may be achieved by rotating the driving rod suchthat the rod moves proximally with the ratchet pawls engaged against thethreads of the rod.

In other embodiments, the device comprises a driving means comprisingfor example, a pneumatic grip, a hook, a latch, a grabbing device, thegripping mechanism described further herein, an element adapted andconfigured for manually pushing the driving rod distally, or anothermechanical means of moving the rod and the implant distally to distractthe arms and insert the implant. These and similar embodiments will beapparent to the person skilled in the art upon consideration ofalternative embodiments described herein.

Further depicted in FIG. 2A is an implant interface 248, an implantdepth stop 246, an implant depth adjustor 242, and an implant coupler240 all of which are adapted and configured to cooperate with the arms252A, 252B and the driving rod 226 and the implant to drive the implantdistally, to distract the vertebrae, and to place the implant within theintervertebral space at a controlled depth. Also shown is the arm pivot214 and the arm spring 216, which allow outward motion of the arms 252A,252B away from the axis 218 of the driving rod 226 as the implant andimplant interface 248 are driven distally. Further depicted in thisfigure is a first rotation element 234 and second rotation element 262,which together allow the handle 228 and the driving rod 226 to rotaterelative to the arms 252A, 252B, the implant interface 248, and theimplant.

In some embodiments, the vertebral distractor-inserter 268 comprises aratchet drive mechanism 224, which comprises an activating lever 202mounted to the housing 236 by an activating lever pivot 204, a firstratchet pawl 232 coupled to the activating lever 202 and adapted toengage the ratchet teeth 210 and move the driving rod 226 distallyrelative to the housing 236, and an engaging element to oppose proximalmotion of the driving rod relative to the housing. The engaging elementcan be, for example, a gripping element 470 as shown in FIG. 5, agrabbing element, a hooking element, a pressurized holding element; orit can be a manual pushing or holding element.

In some embodiments the ratchet drive mechanism 224 comprises anactivating lever spring 206 coupled to the activating lever 202 and thehandle 228, wherein the activating lever spring 206 opposes proximalmovement of the lever 202 relative to the handle 228. In someembodiments of the distractor-inserter 268, the ratchet drive mechanism224 comprises a first pawl spring 230 that opposes downward movement ofthe first pawl 232 and a second pawl spring 258 that opposes downwardmovement of the second pawl 260.

In some embodiments of the distractor-inserter 268, the driving rod 226comprises a distal end and an implant interface 248 coupled to thedistal end of the driving rod 226. In some embodiments, thedistractor-inserter 268 comprises an implant in contact with the implantinterface 248, whereby distal motion of the driving rod 226 impartsdistal motion to the implant through the implant interface 248; anddistal motion of the implant in turn forces the opposing arms 252A, 252Bapart.

In some embodiments, each opposing arm 252A, 252B comprises an arm pivot214. Some embodiments comprise a pair of opposing arms 252A, 252Bcomprising an arm spring 216. Some embodiments comprise an opposing arm252A, 252B comprising an arm depth guard 212. In some embodiments, theimplant interface 248 comprises an implant coupler 240.

FIG. 3B shows a cutaway side view of the housing 236 of an embodiment ofthe device 268 having ratchet teeth 210 engaged by the drive mechanism224 wherein the activating lever 202 is in a first position. A firstratchet pawl 232 engages the ratchet teeth 210 of the driving rod 226and a first pawl spring 230 opposes motion of the first pawl 232 awayfrom the driving rod 226 (downward, in the depicted embodiment,although, it could be in any direction away from the driving rod 226).Also shown is a second ratchet pawl 260. A second pawl spring 258opposes motion of the second pawl 260 away from the driving rod 226(downward, in this case, although it could be in any direction away fromthe driving rod 226). Further depicted is the activating lever pivot 204about which the activating lever 202 pivots to drive the driving rod 226and, therefore, the implant distally by engaging and moving the ratchetteeth 210 distally when the activating lever 202 is moved toward thehandle 228. Also depicted is the activating lever spring 206, whichopposes activating lever 202 movement toward the handle 228, and whichis capable of moving the activating lever 202 away from the handle 228when the activating lever 202 is released.

FIG. 3C shows a cutaway side view of the housing of an embodiment of thedevice having ratchet teeth 210 engaged by the drive mechanism 224,wherein the activating lever 202 is in a second position toward thehandle 228. The drive mechanism 224, the first ratchet pawl 232, and thedriving rod 226 are shown in as they appear when the activating lever202 is moved toward the handle 228. As can be seen, movement of theactivating lever 202 toward the handle 228 causes the first ratchet pawl232, and the driving rod 226, through engagement of the ratchet pawl 232with the ratchet teeth 210 of the driving rod 226, to move distallyrelative to the housing 236.

In some embodiments, the vertebral distractor-inserter 268 is adaptedfor single-handed use. In such an embodiment, the vertebraldistractor-inserter 268 is adapted for substantially single-handeddistraction of vertebrae and insertion of a vertebral implant.

It is to be understood in regard to the phrase “single-handed,” thefunctions of holding the device in place and advancing the rod 226 andimplant may in most instances be performed with a single hand. However,it is also noted that in some cases, depending upon operator preferenceand the vagaries of patient physiology, two hands may be used, e.g. toimpart greater force to the lever 202, without departing from the spiritand scope of the invention. The phrase “single-handed” thusdistinguishes embodiments of the invention over distractor-inserterdevices in which the device is held in place with one hand and theimplant is advanced distally by twisting or striking an implant arm. Itis considered that whether used with one hand or two, the device of thepresent invention provides force to both distract vertebrae and advancethe implant with lessened torque, impact force or other physiologicallydisruptive forces, and thus less trauma to the patient, than isgenerally required with previously known devices. In currently preferredembodiments, the device of the present invention also permits theoperator to hold the device in place and impart force for distractionand insertion with a single hand. In addition to the aforementionedadvantages, single handed use is amenable to less invasive surgery thantwo-handed use.

Some embodiments of the device are adapted and configured to allowretraction of the implant interface and the driving rod relative to thearms of the device. This may be achieved in a number of ways. In theembodiment of the device 368 depicted in FIG. 4A, a cutaway side view ofthe device 368 is shown having ratchet teeth 310 disengaged forretraction of the driving rod 326. The driving rod of this embodimenthas a surface 366 comprising a substantially smooth area 364 and ratchetteeth 310. When the knob 350 is turned about the axis 318, preferablywith knob 350, such that the ratchet teeth 310 are no longer engaged bythe ratchet pawl 332, or the ratchet pawls 332, 360 if there are two,the driving rod 326 is free to be moved proximally (or retracted)relative to the housing 336 and the arms 352. Although this action isfavorably carried out by the operator holding the handle 328 in one handand turning the knob 350 with the other, this action is not to beinterpreted as derogating in any way single-handed operation of thedevice 368, as single-handed operation generally refers tosimultaneously holding the handle 328 and imparting drive force to thedriving arm 326 with a single hand, and that only in most cases. As thedriving rod 326 may be easily disengaged from the pawls 332, 360 with,for example, a single 180° twist about the axis 318, it is consideredthat the present invention provides for easier and faster retraction ofthe driving arm 326 than is provided by previously known devices thatrequire screwing the arm backwards.

In another embodiment, the driving rod 326 may comprise a threadingaround the driving rod instead of ratchet teeth, wherein the ratchetpawl 332 or ratchet pawls 332, 360 if there are two, may engage thethreads instead of ratchet teeth. To retract the rod 326, rather thanturning the driving rod 326 until the pawl(s) 332, 360 disengages theteeth, and then pulling the rod 326 proximally, the rod 326 and,thereby, the implant interface 248, may be retracted by turning the rod326 around the long axis of the rod 326. In this embodiment, the rodthreads are not disengaged from at least the first ratchet pawl 332.

Other embodiments may comprise combinations of threads, ratchet teeth310, and/or a substantially smooth area 364 along the driving rodsurface 366, and a combination of ratcheting and gripping elements toprovide the controlled distal and proximal movement of the driving rod326, the implant, and implant interface 248 relative to the arms 352A,352B, and to the housing 336.

Likewise, the embodiment of FIG. 4B shows a cutaway side view thehousing 336 of an embodiment of the device 368 having ratchet teeth 310of the driving rod 326 disengaged from the first ratchet pawl 332 andsecond ratchet pawl 360 for retraction of the driving rod 326. Alsoshown is the substantially smooth area 364 of the driving rod 326surface 366 which allows proximal retraction of the driving rod 326 and,thereby, the implant interface 248.

If needed or desired, retraction of the device 368 using the featuresand methods described herein may also allow retraction of the implantprior to insertion of the implant between the vertebrae.

In some embodiments, the ratchet teeth 310 extend along the driving rod326 a length sufficient to allow the arms 352 to touch when the implantis loaded prior to distraction and to allow the implant to be insertedbetween the vertebrae. In some embodiments, for example, the ratchetteeth 310 extend along the length of the driving rod 326 for betweenabout 6 and about 10 inches, for about 8 inches, for about 12 inches,for about 16 inches, for at least 3 inches, or for the entire length ofthe rod. In referring to the ratchet teeth length along the rod, “about”refers to variations of 0.5 inches to 1 inch, or of 1 inch to 2 inches.

In some embodiments, the surface 366 of the driving rod 326 comprises anarea 364 that is substantially free of ratchet teeth on a contiguouslongitudinal surface 366 of the driving rod, and the driving rod 326 ismovable proximally relative to the housing 336 upon rotation of the rod326 about its axis 318 such that the ratchet pawls 332, 360 are incontact with the contiguous longitudinal surface 364 that is free ofratchet teeth. In some embodiments, the ratchet teeth 310 disengage fromfirst and second ratchet pawls 332, 360 upon rotation of the driving rod326 about its axis 318. In some embodiments, the driving rod 326comprises a proximal end having a knob 350.

FIG. 5A shows a non-ratcheting embodiment of the device 468. The device468 has a pair of opposing arms 452A, 452B and two gripping elements470, 474, wherein the first gripping element 470 is adapted andconfigured to grip and drive the driving rod 426 distally when theactivating lever 402 is moved toward the handle 428. The second grippingelement 474 allows distal movement of the driving rod 426, but opposesproximal motion of the driving rod 426 when the activating lever 402 isreleased and allowed to move away from the handle 428, for example, toits original resting (first) position. The first gripping element 470also releases its grip on the driving rod 426 when the lever 402 ismoved away from the handle 428, for example, to its original restingposition. The first gripping spring 472 moves the first gripping element470 proximally when the activating lever 402 is released. The firstgripping element 470 is adapted and configured to only grip the drivingrod 426 upon driving rod distal motion. Similarly, in the embodiment ofFIG. 5, the second gripping element 474 is adapted and configured toonly grip the driving rod 426 upon driving rod proximal motion.

FIG. 5B shows a cutaway side view of the housing 436 of a non-ratchetingembodiment of the device 468. The first gripping spring 472 opposes thedistal motion of the first gripping element 470 and the driving rod 426that an operator causes by moving the activating lever 402 toward thehandle 428. A second gripping spring 476 opposes proximal motion of thedriving rod 426 when the lever 402 moves away from the handle 428.Movement of the lever 402 away from the handle 428 may be manuallyforced, or may be the result of an activating lever spring 206 withinthe handle 428 and attached to the activating lever pivot 204 whichopposes movement of the lever 402 toward the handle 428. Also depictedis a gripping release lever 478, which is adapted to permit release thesecond gripping member 474 to allow the driving rod 426 to be retracted.

Some embodiments comprise a drive mechanism 424 comprising at least onegripping element 470 which opposes proximal motion of the drivemechanism 412. Activating the lever 402 drives the implant distally bymoving the driving rod 426. As the activating lever 402 returns to itsoriginal position, the first gripping element 470 releases the drivingrod, however the second gripping element 474 opposes proximal motion ofthe driving rod 426 and the implant. The drive mechanism may comprise agripping spring, 472, or 476, or two gripping springs 472 and 476.

In some embodiments of the distractor-inserter 468, the drive mechanism424 comprises a gripping element 474 and a ratcheting drive mechanism asdescribed previously. Some embodiments comprise other means for drivingimplant distally. These means can be other mechanical mechanisms capableof allowing unidirectional movement, along with a release mechanism forreversing such unidirectional movement. Some embodiments comprise othermeans for distracting the arms. The means for distracting may be othertools altogether through which the distractor-inserter may be placed andused to place the implant.

FIGS. 6A & 6B depict views of an embodiment of the device 568 showingrelative rotation of the arms 552A, 552B and the handle 528. Also shownin these views are at least one arm depth guard 512 and the activatinglever 502. In use, the patient is stationary, and thus the arms 552A,552B of the device 568 and the implant must remain in a fixed positionrelative to the patient during distraction and insertion for patientsafety and for optimal implantation results. However, the user of thedevice 568 may need to be at a variety of angles relative to thepatient; thus, the device is adapted to allow distraction and insertionin a more ergonomic manner for the user and, thus, a safer manner forthe patient. This is achieved by allowing at least one degree of freedomof rotation in the device 568. That is, the device 568 is adapted toallow rotation of the handle 528, activating lever 502, and housing 536relative to the arms 552A, 552B and the implant, about the axis 218 ofthe driving rod 226. This is achieved by providing at least one rotationelement 234 (not shown in FIG. 6, shown in FIG. 3A) that allows freerotation of these elements relative to each other.

FIG. 6A shows the axial view of the device 568 looking from the distalend to the proximal end of the device 568. In this view, the arms 552A,552B are in a neutral position relative to the housing 536. In FIG. 6B,also an axial view of the device 568 looking from the distal end to theproximal end of the device 568, the arms 552A, 552B are rotated relativeto the housing 536 about the driving rod axis 218. While it may appearthat the arms 552A, 552B are rotated, in use the rotation is relative,and the user will more likely rotate the housing 536 and the activatinglever 502 relative to the arms 552A, 552B, keeping the arms 552A, 552Band implant aligned appropriately with the vertebral anatomy of thepatient.

In some embodiments, a vertebral distractor-inserter 568 comprises apair of opposing arms 552A, 552B, a housing 536 in mechanicalcommunication with the pair of opposing arms 552A, 552B and rotatableabout an axis 218 extending between the opposing arms 552A, 552B, and adriving rod 226 extending through at least a portion of the housing 536and between the pair of opposing arms 552A, 552B. Some embodimentscomprise a distal end having an implant interface 248, wherein thehousing 536 and at least a portion of the driving rod 226 are rotatablerelative to the pair of opposing arms 552A, 552B and the implantinterface 248. Some embodiments further comprise an implant interface248 comprising an interface rotation element 262, whereby the interfacerotation element allows rod 226 rotation relative to the pair ofopposing arms 552A, 552B. Some embodiments further comprise a housing536 comprising a housing rotation element 234, whereby the housingrotation element 234 allows housing 536 and rod 226 rotation relative tothe pair of opposing arms 552A, 552B.

In some embodiments, a vertebral distractor-inserter 568 comprises apair of opposing arms 552A, 552B, a housing 536 in mechanicalcommunication with the pair of opposing arms 552A, 552B and rotatableabout an axis 218 extending between the opposing arms 552A, 552B, adriving rod 226 extending through at least a portion of the housing 536and between the pair of opposing arms 552A, 552B, and a drive mechanism224 adapted to move the driving rod 226 distally relative to the housing536.

In some embodiments of a rotatable vertebral distractor-inserter 536,the vertebral distractor-inserter comprises a drive mechanism 224.Embodiments of the drive mechanism are described herein.

FIGS. 7A & 7B depict views of an embodiment of the device 668 having animplant depth adjustment feature. FIG. 7A shows a depth adjustor 642 atits distal-most setting, which results in the implant moving beyond thedistal end of the arms 652A, 652B the least distance. When the implantdepth adjustor 642 is moved proximally, moving the depth stop 646distally relative to the implant or the implant coupler 640, or both, animplant at the distal end of the implant interface 648 can move fartherdistally into the space between the vertebrae because the depth stop 646is more proximal than when the adjustor 642 is at its distal-mostsetting. FIG. 7B shows an intermediate setting for the implant depthadjustor 642, wherein the implant can move more distally relative to thedistal end of the arms 652A, 652B than the implant can when the adjustor642 is at its distal-most setting, as is depicted in FIG. 7A. Theimplant depth adjustor 642 can be threaded proximally and distally tomove the implant depth stop 646 and control, thereby, the distal depthachievable by the implant using the device 668. Other mechanisms foradjusting this depth are possible including, for example, a ratchet, apeg, a clamp, and a grip. In some embodiments, the implant depth stop646 will be adjusted before placing the distal ends of the arms 452A,452B into the intervertebral space and will remain in the same positionthroughout the procedure. The operator may pre-determine the implantdepth in any art-recognized means, e.g. by measuring the depth withvarious imaging techniques or, after the vertebrae have been accessed,by in situ measurement methods. Since adjustment of the implant depthgenerally occurs before the device is inserted into the patient, suchadjustment does not derogate the single-handed use of the device, asexplained with reference to other steps ancillary to distraction andinsertion, above.

In some embodiments, the invention provides a vertebraldistractor-inserter 668 comprising a housing 136, a pair of opposingarms 652A, 652B in mechanical communication with the housing 136, adriving rod 626 extending through at least a portion of the housing 136and between the pair of opposing arms 652A, 652B, a drive mechanism 224adapted to move the driving rod 626 distally relative to the housing136, and an implant depth adjustor 642 that is adjustable to a pluralityof implant depth settings and is adapted to push the distractor-inserter668 proximally upon insertion of an implant to a selected implant depthsetting. The implant depth adjustor 642 may optionally comprise animplant depth stop 646. Example drive mechanisms are previouslydescribed herein. This vertebral distractor-inserter 668 may beratcheting, gripping, a combination of these, or of another typealtogether. Any distractor-inserter described herein may be adapted forsingle-handed use. It may also or alternatively comprise an implantinterface 648 as described herein. It may also be adapted such that thehousing 136 and at least a portion of the driving rod 626 are rotatableabout an axis 118 extending between the opposing arms 652A, 652B, asdescribed herein.

FIG. 8 depicts a view of an embodiment of the device 768 in use showingdistraction of adjacent vertebrae 780. Shown is the distal end of adevice 768 having opposing arms 752A, 752B, arm depth guards 712, adriving rod 726 having an implant interface 748 having an implant depthadjustor 742 and an implant depth stop 746 at the driving rod 726 distalend. Also shown is an implant 738 at the distal end of the implantinterface 748 which has distracted the arms 752A, 752B and is positionedbetween the vertebrae 780. As the driving rod 726 is moved distallyrelative to the arms 752A, 752B, the arms 752A, 752B will be urgedproximally out of the space between the vertebrae 780; but the implant738 will remain between the vertebrae 780. FIG. 9 depicts a view of anembodiment of the device 868 in use showing insertion of an implant 838between distracted vertebrae 880 wherein the arms 852A, 852B and the armdepth guards 812 of the arms 852A, 852B have been urged proximally outof the space between the vertebrae 880, and the implant 838 is in directcontact with and sits between the vertebrae 880. The implant 880 cannotmove distally when the implant depth stop 846 abuts the vertebra 880.

Multiple elements may be combined in the devices contemplated herein.Additionally, in some embodiments, the invention provides a method fordistracting adjacent vertebrae 880 and inserting an implant 838 betweenthe distracted vertebrae 880. The method comprises mounting the implant838 to a driving rod 826 of a vertebral distractor-inserter device 868described herein. The device 868 may having a housing 136, a pair ofopposing arms 152A, 152B in mechanical communication with the housing136 having a distal end, and a drive mechanism 224 in mechanicalcommunication with the driving rod 826. The driving rod 826 extendsthrough at least a portion of the housing 136 and between the pair ofopposing arms 852A, 852B. The method may further comprise positioningthe distal end of the pair of arms 852A, 852B between the vertebrae 880,distracting the vertebrae 880 by single-handed operation of thevertebral distractor-inserter 868, inserting the implant 838 between thedistracted vertebrae 880 by single-handed operation of the vertebraldistractor-inserter 868, and retracting the pair of opposing arms 852A,852B from between the vertebrae 880.

In some embodiments, the invention provides a method for distractingadjacent vertebrae 880 and inserting an implant 838 between thedistracted vertebrae 880, wherein the distracting step comprisesactivating the drive mechanism 224 using one hand. The step ofactivating moves the implant 880 distally and distracts the pair ofopposing arms 852A, 852B. In some embodiments of the method, theinserting comprises advancing the implant 880 into the distracted spacebetween the vertebrae 880. In some embodiments of the method, advancingthe implant comprises activating the drive mechanism 224 using one handand extending the implant 880 beyond the distal end of the pair ofopposing arms 852A, 852B. In some embodiments, the method comprises theadditional step of releasing the implant 880 from thedistractor-inserter 868.

In some embodiments of the method for distracting adjacent vertebrae 880and inserting an implant 838 between the distracted vertebrae 880 thepositioning step comprises urging the pair of arms 852A, 852B betweenthe vertebrae 880 up to the position where a depth guard 812 of the arms852A, 852B contacts the vertebrae 880. In some embodiments, thepositioning step comprises urging the pair of arms 852A, 852B betweenthe vertebrae 880 up to a distal depth of at most 75 mm, or at leastabout 25 mm, or between about 35 mm and 55 mm. When referring to distaldepth herein, “about” refers to variations in depth of between 1 mm and2 mm, or between 2 mm and 5 mm. In some embodiments, the distal depth isthe distance from the depth guard 812 to the distal end of the pair ofopposing arms 852A, 852B. In some embodiments, the arms 852A, 852B areinserted between the vertebrae 880 up to a distal depth such that thedepth guard 812 is proximal to, but not abutting, the proximal side ofthe vertebrae 880. In some embodiments, the depth guard 812 is proximalto and abutting, or contacting, the proximal side of the vertebrae 880.

In some embodiments, mounting the implant comprises the step ofadjusting the implant depth adjustor 642 to control the maximum distalimplant depth achievable during the inserting step. In a relatedembodiment, the implant depth achievable is a maximum of about 25 mm, aminimum of about 0 mm, or between about 3 mm and 8 mm. When referring toimplant herein, “about” refers to variations in depth of between 1 mmand 2 mm, or between 2 mm and 5 mm. The implant depth is measured fromthe distal end of the depth stop 646 to the distal end of the implantinterface 648.

In some embodiments, insertion of the implant comprises the step ofretracting the pair of opposing arms 852A, 852B from between thevertebrae 880 by abutting the implant depth adjustor 642 against aproximal side of the vertebrae 880 and activating the drive mechanism224 using one hand.

In some embodiments, the invention provides a method comprisingactivating the drive mechanism 224 wherein the activating comprises thestep of ratcheting the driving rod 826 distally, wherein the driving rod826 comprises an axis 218 and a surface 366 with a plurality of angledratchet teeth 210 on at least a portion of the surface 366. In such anembodiment, the drive mechanism 224 may comprise an activating lever 202capable of movement between a first position and a second position andmounted to the housing 236 by an activating lever pivot 204. The drivemechanism may further comprise a first ratchet pawl 232 coupled to theactivating lever 202 and adapted to engage the ratchet teeth 210. Thefirst ratchet pawl may move the driving rod 826 distally relative to thehousing 236 as described herein. The drive mechanism may furthercomprise a second ratchet pawl 260 adapted to engage the ratchet teeth210 and oppose proximal motion of the driving rod 826 relative to thehousing 236 as described herein.

In some embodiments, the invention provides a method comprising grippingthe rod 424 and moving the driving rod 424 distally wherein thedistractor-inserter is an embodiment as described herein. In someembodiments, the step of ratcheting comprises the step of applying aforce to the activating lever 402 to move the lever 402 toward thesecond position. In some embodiments of the method, the step ofratcheting further comprises the steps of releasing the force on theactivating lever 402 and allowing the activating lever spring 206 tomove the activating lever 402 toward the first position.

In some embodiments, the invention provides a method comprising rotatingthe housing 236 and at least a portion of the driving rod 226 relativeto the pair of opposing arms 252A, 252B and to the implant 838.

In some embodiments, the housing 236 is rotatable about an axis 218extending between the opposing arms 252A, 252B relative to the arms252A, 252B and to the implant 838, and wherein at least a portion of thedriving rod 226 is rotatable about the axis 218 extending between theopposing arms 252A, 252B relative to the pair of opposing arms 252A,252B and to the implant 838. This method may further comprise activatinga drive mechanism 224 wherein the activating step moves the implantdistally and distracts the pair of opposing arms 252A, 252B. In someembodiments, inserting the implant comprises advancing the implant 838into the distracted space between the vertebrae 880. In someembodiments, the advancing the implant comprises activating the drivemechanism 224 and extending the implant 838 beyond the distal end of thepair of opposing arms 252A, 252B.

In some embodiments, the invention provides a method comprising mountingthe implant 838 to a driving rod 826 of a vertebral distractor-inserter868 having a housing 136, a pair of opposing arms 852A, 852B, and aratchet drive mechanism 224 in mechanical communication with the drivingrod 826. The method further comprises positioning the distal end of thepair of arms 852A, 852B between the vertebrae 880, and distracting thevertebrae 880. Distracting the vertebrae 880 may further compriseactivating the ratchet drive mechanism 224 and inserting the implant 838between the distracted vertebrae 880. Inserting the implant 838 maycomprise advancing the implant 838 into the distracted space between thevertebrae 880, wherein the step of advancing comprises activating theratchet drive mechanism 224 and retracting the pair of opposing arms852A, 852B from between the vertebrae 880.

In some embodiments of the method, the step of activating moves theimplant 838 distally and distracts the pair of opposing arms 852A, 852B.In some embodiments, the distraction is caused by the distal motion ofthe implant 838 having a depth that is greater than the distance betweenthe arms 852A, 852B at the distal end of the device 868. As the implant838 moves distally, the implant 838 contacts the arms 852A, 852B andforces them apart, outwardly from the axis of the driving rod 826. Whenthe arms 852A, 852B are forced apart, if the distal ends of the arms852A, 852B are between the vertebrae 880, the distal motion of theimplant 838 also distracts, i.e. opens, the space between the vertebrae880.

Alternatively, in another embodiment, the implant interface 848 contactsthe arms 852A, 852B, distracts the arms 852A, 852B, and thus distractsthe vertebrae 880 as the interface 848 is moved distally. In someembodiments, the step of advancing comprises extending the implant 838beyond the distal end of the pair of opposing arms 852A, 852B. In someembodiments, the activating the ratchet drive mechanism 224 comprisesratcheting the driving rod 826 distally, wherein the driving rod 826comprises an axis 218 and a surface 366 with a plurality of angledratchet teeth 210 on at least a portion of the surface 366, and whereinthe ratchet drive mechanism 224 comprises an activating lever 202capable of movement between a first position and a second position andmounted to the housing 136 by an activating lever pivot 204, a firstratchet pawl 232 coupled to the activating lever 202 and adapted toengage the ratchet teeth 210 and move the driving rod 826 distallyrelative to the housing 136, and a second ratchet pawl 260 adapted toengage the ratchet teeth 210 and oppose proximal motion of the drivingrod 826 relative to the housing 136.

In some embodiments, the invention provides a method for ratchetingcomprising the step of applying a force to the activating lever 202 tomove the lever 202 toward the second position. In some embodiments thedrive mechanism 224 comprises a handle 228 attached to the housing 136and an activating lever spring 206 coupled to the activating lever 202and the handle 228, wherein the activating lever spring 206 opposesproximal movement of the lever 202 relative to the handle 228, andwherein the step of ratcheting further comprises the steps of releasingthe force on the activating lever 202 and allowing the activating leverspring 206 to move the activating lever 202 toward the first position.In some embodiments, the method comprises releasing the implant 838 fromthe distractor-inserter 868, wherein the implant 838 was coupled to thedistractor-inserter 868.

In some embodiments, the invention provides a method comprising mountingthe implant 838 to a driving rod 826 of a vertebral distractor-inserter868 having a pair of opposing arms 852A, 852B having a distal end, ahousing 136 in mechanical communication with the pair of opposing arms852A, 852B which is rotatable about an axis 118 extending between theopposing arms 852A, 852B relative to the arms 852A, 852B and to theimplant 838, and a drive mechanism 224 in mechanical communication withthe driving rod 826, wherein the driving rod 826 extends through atleast a portion of the housing 136 and between the pair of opposing arms852A, 852B and wherein at least a portion of the driving rod 826 isrotatable about the axis 118 extending between the opposing arms 852A,852B relative to the pair of opposing arms 852A, 852B and to the implant838, positioning the distal end of the pair of arms 838 between thevertebrae 880, rotating the housing 136 and at least a portion of thedriving rod 826 relative to the pair of opposing arms 852A, 852B and tothe implant 838, distracting the vertebrae 880, inserting the implant838 between the distracted vertebrae 880, and retracting the pair ofopposing arms 852A, 852B from between the vertebrae 880. The distractingmay further comprise activating the drive mechanism 224, wherein theactivating moves the implant 838 distally and distracts the pair ofopposing arms 852A, 852B. The inserting may comprise advancing theimplant 838 into the distracted space between the vertebrae 880. Theadvancing may comprise activating the drive mechanism 224 and extendingthe implant 838 beyond the distal end of the pair of opposing arms 852A,852B.

The method may further comprise ratcheting the driving rod 826 distally,wherein the driving rod 826 comprises an axis 118 and a surface 366 witha plurality of angled ratchet teeth 110 on at least a portion of thesurface 366, and wherein the drive mechanism 224 comprises an activatinglever 102 capable of movement between a first position and a secondposition and mounted to the housing 136 by an activating lever pivot204, a first ratchet pawl 232 coupled to the activating lever 102 andadapted to engage the ratchet teeth 110 and move the driving rod 826distally relative to the housing 136, and a second ratchet pawl 260adapted to engage the ratchet teeth 110 and oppose proximal motion ofthe driving rod 826 relative to the housing 136. The ratcheting cancomprise actions previously described herein.

The positioning can further comprise using a depth adjustor 642 tocontrol the implantation depth between the vertebrae 880. Someembodiments of the method comprise mounting the implant 838 to a drivingrod 826 of a vertebral distractor-inserter 868 having a pair of opposingarms 852A, 852B having a distal end and a depth guard 812, an implantdepth adjustor 642 that is adjustable to a plurality of implant depthsettings, a housing 136 in mechanical communication with the pair ofopposing arms 852A, 852B, and a drive mechanism 224 in mechanicalcommunication with the driving rod 826, wherein the driving rod 826extends through at least a portion of the housing 136 and between thepair of opposing arms 852A, 852B, and wherein the mounting comprises thestep of adjusting the implant depth adjustor 642 to control the maximumdistal implant depth achievable during the inserting step, positioningthe distal end of the pair of arms 852A, 852B between the vertebrae 880,wherein the positioning comprises urging the pair of arms 852A, 852Bbetween the vertebrae 880 up to the position where the depth guard 812contacts the vertebrae 880, distracting the vertebrae 880, inserting theimplant 838 between the distracted vertebrae 880, and retracting thepair of opposing arms 852A, 852B from between the vertebrae 880.

In some embodiments, the invention provides a method for implanting animplant 838 between distracted vertebrae 880 comprising urging whereinthe step of urging moves a pair of arms 852A, 852B between the vertebrae880 up to a distal depth of at most about 75 mm, or at least about 25mm, or between about 35 mm and 55 mm, wherein distal depth is thedistance from a depth guard 812 to the distal end of the pair ofopposing arms 852A, 852B. In some embodiments, the implant depthachievable is a maximum of about 25 mm, a minimum of about 0 mm, orbetween about 3 mm and 8 mm. The implant depth is measured from thedistal end of the depth stop 846 to the distal end of the implantinterface 848. In some embodiments, the distractor-inserter 868 isadapted to push the housing 136 proximally relative to the implant 838upon insertion of the implant 838 to a selected implant depth setting,and the inserting comprises the step of retracting the pair of opposingarms 852A, 852B from between the vertebrae 880 by abutting the arm depthguard 812 against a proximal side of the vertebrae 880 and activatingthe drive mechanism 224.

In some embodiments, the invention provides a vertebraldistractor-inserter, comprising a housing, a pair of opposing arms inmechanical communication with the housing, and a driving means fordriving a rod and an implant at the distal end of the rod distally,wherein the driving means comprises an activating lever and a drivingmechanism activated by the activating lever. The driving means maycomprise a gripping means for gripping the rod while the activatinglever drives the rod distally relative to the housing. Such means isdescribed below and shown in FIGS. 5A & 5B. The driving means maycomprise a ratcheting means for incrementally ratcheting the roddistally as the activating lever is pulled proximally relative to thehousing. Examples of such ratcheting means are described herein and someexample embodiments are shown in FIGS. 2, 3, and 4. The vertebraldistractor-inserter may comprise a holding means for opposing proximalmotion of the rod while resetting the lever after lever activation.Examples of such holding means are described herein. The vertebraldistractor-inserter may comprise a rotating means for allowing operatorrotation of the housing relative to the pair of opposing arms about anaxis extending between the opposing arms. Examples of such rotatingmeans are described herein, and examples are shown in FIGS. 2 and 6. Thevertebral distractor-inserter may comprise a depth-controlling means foradjusting and controlling the depth to which an implant may be insertedby an operator between adjacent vertebrae. Examples of suchdepth-controlling means are described herein, and examples are shown inFIGS. 2, 3, 7, 8, and 9.

FIGS. 10A, 10B, 10C, and 10D depict external views of one currentlypreferred embodiment of the device 168 where the device is used to placethe implant between two vertebrae from a posterior or aposterior-lateral angle. Introducing the device from a posterior orposterior-lateral angle comprises introducing the device into theintervertebral space from the dorsal side of the patient, where theposterior angle is parallel to the axial plane 52 (see FIG. 1B). In someembodiments, the posterior angle is approximately parallel to the axialplane 52 and the sagittal plane 54 of the patient. Alternatively, thedevice can be introduced to the spinal column parallel to the axialplane 52 but at an angle with respect to the sagittal plane 54.

FIG. 10A is a side view of one embodiment of a vertebraldistractor-inserter 168 comprising a housing 136, a pair of opposingarms 152A, 152B in mechanical communication with the housing 136, adriving rod 126 extending through at least a portion of the housing 136and between the pair of opposing arms 152A, 152B, wherein the drivingrod 126 comprises an axis 118 and a surface 166. In some embodiments,the driving rod can comprise a plurality of angled ratchet teeth 110 onat least a portion of the surface 166 of the driving rod 126. The device168 can further comprises a ratchet drive mechanism 124 in mechanicalcommunication with the plurality of angled ratchet teeth on the drivingrod 126 as shown in FIG. 10A. The arms 152A, 152B of the device 168further comprise a depth guard 112 on each arm. The depth guards 112limit the extent to which the arms 152A, 152B can be inserted into theintervertebral space. In some embodiments, the vertebraldistractor-inserter 168 comprises a handle 128 attached to the housing136. In some embodiments, the vertebral distractor-inserter 168 does notcomprise a housing 136. In some embodiments, the housing 136 does notenclose the rod 126. In some embodiments, the rod 126 is external to,but in communication with, the housing 136.

FIG. 10A further depicts an embodiment having an activating lever 102,which is in mechanical communication with the driving rod 126. Theactivating lever 102 is mounted to the housing 136 by an activatinglever pivot 104. Movement of the activating lever 102 in the directionof the handle 128, designated by the arrow in the figure, causes thedriving rod 126 and an implant (not shown) coupled to an implant coupler140 at the distal end of the driving rod 126 to move distally relativeto the housing 136. The mechanical communication between the driving rodand the activating lever may be effected through a number of means. Inthe depicted embodiment the mechanical communication is through aratcheting drive mechanism 124 within the housing 136. The ratchetingmechanism described above can be included with the device. Theratcheting drive mechanism 124 uses at least one ratchet pawl to gripthe ratchet teeth 110 of the driving rod 126 and to drive the implantand the rod 126 distally when the activating lever 102 is moved towardthe handle 128. The ratchet pawl, or in some embodiments, ratchet pawls,of the ratchet drive mechanism 124 further locks the driving rod 126 inplace thereby preventing movement in a proximal direction. In someembodiments, the drive mechanism can be advanced manually. In someembodiments, the drive mechanism is a screw-type drive mechanism wherethe screw drive mechanism interacts with threads located on the drivingrod. In some embodiments, the device further comprises a gripping memberor other suitable holding means for restricting proximal motion of thedriving rod. Activating the lever 102 drives the implant distally bymoving the driving rod 126. As the activating lever 102 returns to itsoriginal position, the gripping element opposes proximal motion of thedriving rod and the implant. In some embodiments at least one grippingmember is present. In some embodiments, more than one gripping member ispresent. The gripping member may comprise, for example, a pneumaticgrip, a hook, a latch, a grabbing device, or any other suitable elementfor restricting proximal motion.

In some embodiments, the vertebral distractor-inserter 168 is adaptedfor single-handed use. In such an embodiment, the vertebraldistractor-inserter 168 is adapted for substantially single-handeddistraction of vertebrae and insertion of a vertebral implant. It is tobe understood in regard to the phrase “single-handed,” the functions ofholding the device in place and advancing the rod 126 and implant may inmost instances be performed with a single hand. However, it is alsonoted that in some cases, depending upon operator preference and thevagaries of patient physiology, two hands may be used, e.g. to impartgreater force to the lever 102, without departing from the spirit andscope of the invention. The phrase “single-handed” thus distinguishesembodiments of the invention over distractor-inserter devices in whichthe device is held in place with one hand and the implant is advanceddistally by twisting or striking an implant arm. It is considered thatwhether used with one hand or two, the device of the present inventionprovides force to both distract vertebrae and advance the implant withlessened torque, impact force or other physiologically disruptiveforces, and thus less trauma to the patient, than is generally requiredwith previously known devices. In currently preferred embodiments, thedevice of the present invention also permits the operator to hold thedevice in place and impart force for distraction and insertion with asingle hand. In addition to the aforementioned advantages, single handeduse is amenable to less invasive surgery than two-handed use.

Some embodiments of the device are adapted and configured to allowretraction of the implant interface and the driving rod relative to thearms of the device. This may be achieved in a number of ways. In theembodiment shown in FIG. 10A, the device comprises a knob 150. The knob150 can be used to facilitate retraction of the driving rod. The drivingrod of this embodiment has a surface 166 comprising a substantiallysmooth area 164 and ratchet teeth 110. When the knob 150 is turned aboutthe axis 118 of the driving rod 126, preferably with knob 150, such thatthe ratchet teeth 110 are no longer engaged by the ratchet pawl, or theratchet pawls, if there are two, the driving rod 126 is free to be movedproximally (or retracted) relative to the housing 136 and the arms 152A,152B. Although this action is favorably carried out by the operatorholding the handle 128 in one hand and turning the knob 150 with theother, this action is not to be interpreted as derogating in any waysingle-handed operation of the device 168, as single-handed operationgenerally refers to simultaneously holding the handle 128 and impartingdrive force to the driving arm 126 with a single hand. As the drivingrod 126 may be easily disengaged from the pawls with, for example, asingle 180° twist about the axis 118, it is considered that the presentinvention provides for easier and faster retraction of the driving arm126 than is provided by previously known devices that require screwingthe arm backwards.

In another embodiment, the driving rod 126 may comprise a threadingaround the driving rod instead of ratchet teeth, wherein the ratchetpawl or ratchet pawls if there are two pawls, of the ratchet drivemechanism may engage the threads instead of ratchet teeth on the drivingrod. To retract the rod 126, rather than turning the driving rod 126until the pawl(s) disengages the teeth, and then pulling the rod 126proximally, the rod 126 and, thereby, the implant coupler 140, may beretracted by turning the rod 126 around the long axis 118 of the drivingrod 126. In this embodiment, the rod threads are not disengaged from atleast the first ratchet pawl 132.

Other embodiments may comprise combinations of threads, ratchet teeth110, and/or a substantially smooth area along the driving rod surface166, and a combination of ratcheting and gripping elements to providethe controlled distal and proximal movement of the driving rod 126, theimplant, and implant coupler 140 relative to the arms 152A, 152B, and tothe housing 136.

If needed or desired, retraction of the device 168 using the featuresand methods described herein may also allow retraction of the implantprior to insertion of the implant between the vertebrae.

In some embodiments, the ratchet teeth 110 extend along the driving rod126 a length sufficient to allow the arms 152A, 152B to touch when theimplant is loaded prior to distraction and to allow the implant to beinserted between the vertebrae. In some embodiments, for example, theratchet teeth 110 extend along the length of the driving rod 126 forbetween about 6 and about 10 inches, for about 8 inches, for about 12inches, for about 16 inches, for at least 3 inches, or for the entirelength of the rod. In referring to the ratchet teeth length along therod, “about” refers to variations of 0.5 inches to 1 inch, or of 1 inchto 2 inches.

In some embodiments of the distractor-inserter 168, the drive mechanism124 comprises a gripping element and a ratcheting drive mechanism asdescribed previously. Some embodiments comprise other means for drivingimplant distally. These means can be other mechanical mechanisms capableof allowing unidirectional movement, along with a release mechanism forreversing such unidirectional movement. Some embodiments comprise othermeans for distracting the arms. The means for distracting may be othertools altogether through which the distractor-inserter may be placed andused to place the implant.

FIG. 10B illustrates a similar embodiment of the device 168 as viewedfrom the proximal end with a driving rod 126 and the implant coupler 140in the fully extended position. The arms 152A, 152B of the device 168are in a closed configuration when the driving rod 126 is in the fullyextended position. FIG. 10B also illustrates the resting position of thedevice 168 after the implant has been inserted.

FIG. 10C depicts a top view of an embodiment of the device 168 with thedriving rod and the implant coupler 140 in a fully retracted position asindicated by the arms 152A, 152B touching each other. In this view, thehousing 136 is shown along with the driving rod 126, which extendsthrough the housing 136. This view also shows a knob 150 on the proximalend of the driving rod 126.

FIG. 10D depicts an embodiment of the device as viewed from the distalend. The housing 136 is shown along with the driving rod 126, whichextends through the housing 136. The implant coupler 140 abuts theimplant and transfers force from the driving rod 126 to the implant,which in turn forces the first arm 152B and the second arm 152A apart,thereby providing distracting force to the vertebrae. The embodiment hasan arm depth guard 112, which determines the maximum depth to which thearms 152A, 152B can be inserted between the vertebrae duringdistraction. As the activating lever 102 is moved toward the handle 128,the driving rod advances forward. As the implant is advanced into theintervertebral space, the forward motion of the driving rod 126 causingthe arms 152A, 152B to retract from the vertebrae 180A, 180B.

FIG. 11A is a view of the device 168 in use as viewed from the undersideof the device 168. As shown in FIG. 11A, the device uses aposterior-lateral angle to interact with the vertebra 180A, 180B. Thearms 152A, 152B are inserted into the intervertebral space up to thelocation of the arm depth guard 112 parallel to the axial plane 52 andthe sagittal plane 54. The user or surgeon then moves the activatinglever 102 in the direction of the handle 128 multiple times. Aratcheting mechanism located within the housing 136 engages theratcheting teeth 110 on the driving rod 126. Each movement of theactivating lever advances the driving rod forward, thereby advancing theimplant coupler 140 and the implant 138. As the implant 138 is advancedforward, the arms 152A, 152B are forced apart thereby distracting thevertebrae 180A, 180B, as shown in FIG. 11A. The user can continue toadvance the implant forward, the implant thereby passing through thearms and thereby entering the intervertebral space.

FIG. 11B is a close-up view of the device in use showing distraction ofadjacent vertebrae 180A, 180B from the posterior side of the vertebralcolumn. Shown is the distal end 170 of a device 168 shown in FIG. 11Ahaving opposing arms 152A, 152B, arm depth guards 112, a driving rod 126having an implant coupler 140 at the driving rod 126 distal end. Alsoshown is an implant 138 at the distal end of the implant coupler 140,which has distracted the arms 152A, 152B of the device 168, and ispositioned between the vertebrae 180A, 180B. As the driving rod 126continues to moves distally relative to the arms 152A, 152B, the arms152A, 152B will be urged proximally out of the space between thevertebrae 180A, 180B. However, the implant 138 remains between thevertebrae 180A, 180B.

A suitable implant can be used with the device described herein. In someembodiments, the implant has laterally opposing walls that aresubstantially parallel to the axis of insertion, as seen in FIG. 12A.FIG. 12A is one embodiment of an implant 138 have sides substantiallyparallel to the axis of insertion as viewed from the side. FIG. 12B is aview of the implant 138 of FIG. 12A as viewed from the top. FIG. 12C isa perspective view of the implant 138 shown in FIG. 12A. In someembodiments, an implant can be inserted on one side of the spinousprocess using at an angle parallel to the axial plane 52 and thesagittal plane 54. Additionally, more than one implant can be insertedinto the intervertebral space. For example, a second implant can beinserted on the side contralateral to the first implant. In someembodiments, more than one implant can be inserted into theintervertebral space simultaneously. The implant can have a box-likestructure, e.g., a square box or cube structure. Alternatively, theimplant can be a prism, such as a rectangular prism, or a polygonalprism. The implant can have any suitable 3-dimensional configuration.The implant can have a length running in the proximal-distal direction,a width, and a height. In some embodiments, the length, width, andheight are the same. Alternatively, the length, width, and height aredifferent. The length can be longer than the width and the height. Insome embodiments, the implant is a disc-like structure having a radius.The disc-like structure can also have a height. The disc-like structurecan comprise a substantially circular base, a translated copy of thebase, and a side joining the base and translated base. The disc can alsocomprise side segments joining the base and translated base. In someembodiments, the disc-like structure comprises a circular base with aradius that is the same at every location. Alternatively, the disc-likestructure comprises an oval base. In some embodiment, the implant 138can comprise a serrated edge 152, as shown in FIGS. 11A and 11B. Theserrated edge of the implant 138 can interact with the surface of thevertebrae. The serrated edge 152 of the implant 138 facilitates theplacement of the implant 138 as well as helps to ensure the immobilityof the implant 138. A serrated edge 152 can be located on one side ofthe implant. In some embodiments, both edges of the implant 138 cancomprise a serrated edge 152.

In some embodiments, the implant can comprise laterally opposing wallsthat are substantially curved. One embodiment of an implant 138 withcurved laterally opposing walls is shown in FIG. 12D. FIG. 12E is a viewof the implant 138 of FIG. 12D as viewed from the top. A perspectiveview of an implant 138 with curved walls is illustrated in FIG. 12F. Insome embodiments, the implant has one laterally opposing wall that issubstantially parallel to the axis of insertion and one laterallyopposing wall that is substantially curved. The curved wall canfacilitate the placement of the implant in the intervertebral space. Theimplant can be inserted into the intervertebral space and then adjusteduntil positioned in a desired location. The implant can be inserted intothe intervertebral space and repositioned such that the implant ispositioned in the anterior intervertebral space. In some embodiments,the implant can be positioned such that substantially half of theimplant is positioned on one side of the spinous process andsubstantially half of the implant is positioned on the other side of thespinous process. The implant can be positioned such that a majority ofthe implant is positioned on one side of the spinous process. Theimplant can comprise a curved wall that is insertable around the spinalcolumn. In some embodiments more than one implant with curved laterallyopposing walls can be inserted into the intervertebral space. Theimplant can comprise a serrated edge 152 which interacts with thesurface of the vertebrae. The serrated edge 152 facilitates theplacement of the implant 138 as well as helps to ensure the immobilityof the implant 138. A serrated edge 152 can be located on one side ofthe implant. In some embodiments, both edges of the implant can comprisea serrated edge 152, as shown in FIGS. 11A and 11B.

FIG. 13A is a view of the device 168 in use with an alternativeembodiment of an implant 138 as viewed from the underside of the device.As shown in FIG. 13A, the device interacts with the vertebrae 180A, 180Busing a posterior or posterior-lateral angle. The device can approachthe posterior of the vertebral column parallel to the axial plane 52 andthe sagittal plane 54 and can be inserted into the intervertebral spacefrom either side of the spinous process. FIG. 13A, illustrates a devicethat can be used to insert an implant into the intervertebral spacecontralateral to the side illustrated in FIG. 11A. The arms 152A, 152Bare inserted into the intervertebral space up to the location of the armdepth guard 112. The user or surgeon then moves the activating lever 102in the direction of the handle 128 multiple times. A ratchetingmechanism located within the housing 136 engages the ratcheting teeth110 on the driving rod 126. Each movement of the activating leveradvances the driving rod forward, thereby advancing the implant coupler140 and the implant 138. As the implant 138 is advanced forward, thearms 152A, 152B are forced apart thereby distracting the vertebrae 180A,180B, as shown in FIG. 13A. The implant advances forward and enters theintervertebral space.

FIG. 13B is a close-up view of the device 168 in use showing distractionof adjacent vertebrae 180A, 180B using a posterior approach, wherein thedevice is introduced parallel to the axial plane 52 and the sagittalplane 54. Shown is the distal end 170 of a device 168 having opposingarms 152A, 152B, arm depth guards 112, and a driving rod 126 having animplant interface 148 at the driving rod 126 distal end. Also shown isan implant 138 at the distal end of the implant interface 148, which hasdistracted the arms 152A, 152B of the device 168, and which accesses theintervertebral space from the posterior side of the vertebral column. Asthe driving rod 126 continues to moves distally relative to the arms152A, 152B, the arms 152A, 152B are distracted and the implant 138passes through the arms 152A, 152B into the intervertebral space. As thedriving rod 126 is further advanced distally relative to the arms 152A,152B, the arms 152A, 152B will be urged proximally out of the spacebetween the vertebrae 180A, 180B. The implant 138 remains between thevertebrae 180A, 180B.

A suitable implant can be used with the device described herein. In someembodiments, the implant has laterally opposing walls that aresubstantially parallel to the axis of insertion, as seen in FIG. 14A.FIG. 14A is one embodiment of an implant 138 have sides substantiallyparallel to the axis of insertion as viewed from the side. In someembodiments, the implant can have solid sides. Alternatively, theimplant 138 can have cut outs in the sides as shown in FIG. 14A. FIG.14B is a view of the implant 138 of FIG. 14A as viewed from the top.FIG. 14C is a perspective view of the implant 138 shown in FIG. 14A. Insome embodiments, an implant can be inserted on one side of the spinousprocess using a posterior angle. Additionally, more than one implant canbe inserted into the intervertebral space. For example, a second implantcan be inserted on the other side of the spinous process. In someembodiments, more than one implant can be inserted into theintervertebral space simultaneously. The implant can have a box-likestructure, e.g., a square box or cube structure. Alternatively, theimplant can be a prism, such as a rectangular prism, or a polygonalprism. The implant can have any suitable 3-dimensional configuration.The implant can have a length, width, and height. In some embodiments,the length, width, and height are the same. Alternatively, the length,width, and height are different. In some embodiments, the implant is adisc-like structure having a radius. The disc-like structure can alsohave a height. The disc-like structure can comprise a substantiallycircular base, a translated copy of the base, and a side joining thebase and translated base. The disc can also comprise side segmentsjoining the base and translated base. In some embodiments, the disc-likestructure comprises a circular base with a radius that is the same atevery location. Alternatively, the disc-like structure comprises an ovalbase. In some embodiment, the implant 138 can comprise a serrated edge152, as shown in FIGS. 13A and 13B. The serrated edge of the implant 138can interact with the surface of the vertebrae. The serrated edge 152 ofthe implant 138 facilitates the placement of the implant 138 as well ashelps to ensure the immobility of the implant 138. A serrated edge 152can be located on one side of the implant. In some embodiments, bothedges of the implant 138 can comprise a serrated edge 152, as shown inFIGS. 13A and 13B.

In some embodiments, the implant can comprise laterally opposing wallsthat are substantially curved. One embodiment of an implant 138 withcurved laterally opposing walls is shown in FIG. 14D. FIG. 14D is a sideview of the implant. In some embodiments, the implant can have solidsides. Alternatively, the implant 138 can have cut outs in the sides asshown in FIG. 14D. FIG. 14E is a view of the implant 138 of FIG. 14D asviewed from the top. A perspective view of an implant 138 with curvedwalls is illustrated in FIG. 14F. In some embodiments, the implant hasone laterally opposing wall that is substantially parallel to the axisof insertion and one laterally opposing wall that is substantiallycurved. The curved wall can facilitate the placement of the implant inthe intervertebral space. The implant can be inserted into theintervertebral space and then adjusted until positioned in a desiredlocation. In some embodiments, the implant can be positioned such thatsubstantially half of the implant is positioned on one side of thespinous process and substantially half of the implant is positioned onthe other side of the spinous process. The implant can be positionedsuch that a majority of the implant is positioned on one side of thespinous process. The implant can comprise a curved wall that isinsertable around the spinal column. In some embodiments more than oneimplant with curved laterally opposing walls can be inserted into theintervertebral space. The implant can comprise a serrated edge 152 whichinteracts with the surface of the vertebrae. The serrated edge 152facilitates the placement of the implant 138 as well as helps to ensurethe immobility of the implant 138. A serrated edge 152 can be located onone side of the implant. In some embodiments, both edges of the implantcan comprise a serrated edge 152, as shown in FIGS. 13A and 13B.

The device described herein can be used to distract the vertebrae of thespinal column by approaching the spinal column from the posterior sideof the vertebral column, or by using a posterior approach. In someembodiments, the device can approach the posterior side of the vertebralcolumn so that the device is inserted from directly behind the vertebralcolumn. In other words, the device 168 can be inserted into theintervertebral space after entering the intervertebral space from aposterior-lateral angle. The device can enter the intervertebral spaceparallel to the axial plane and at an angle with respect to the sagittalplane, as shown in FIG. 15. As shown in FIG. 15, the device enters theintervertebral space from the side at an angle as opposed to fromdirectly behind or parallel to the axial 52 and sagittal plane 54. Thedevice can be inserted into the intervertebral space from any suitableangle. As shown in FIG. 15, the device interacts with the vertebrae180A, 180B from the posterior side of the vertebral column. The devicecan approach the posterior of the vertebral column and be inserted intothe intervertebral space from either side of the spinous process. Thedevice 168 can be inserted into the intervertebral space parallel to theaxial plane 52 and the sagittal plane 54. Alternatively, the device canbe inserted into the intervertebral space parallel to the axial plane 52but at an angle with respect to sagittal plane as shown in FIG. 15. Insome embodiments, the device is introduced to the spinal column using aposterior angle where the device is introduced at an angle that deviatesfrom the sagittal plane by between about 20 degrees to about 60 degreeswith respect to the sagittal plane. In some embodiments, the device isintroduced to the spinal column using a posterior angle where the deviceis introduced at an angle that deviates from the sagittal plane bybetween about 20 degrees to about 30 degrees with respect to thesagittal plane. In some embodiments, the device is introduced to thespinal column using a posterior angle where the device is introduced atan angle that deviates from the sagittal plane by between about 30degrees to about 40 degrees with respect to the sagittal plane. In someembodiments, the device is introduced to the spinal column using aposterior angle where the device is introduced at an angle that deviatesfrom the sagittal plane by between about 40 degrees to about 50 degreeswith respect to the sagittal plane. In some embodiments, the device isintroduced to the spinal column using a posterior angle where the deviceis introduced at an angle that deviates from the sagittal plane bybetween about 50 degrees to about 60 degrees with respect to thesagittal plane.

As previously described, the arms 152A, 152B are inserted into theintervertebral space up to the location of the arm depth guard 112. Theuser or surgeon then moves the activating lever in the direction of thehandle multiple times. A ratcheting mechanism located within the housing136 engages the ratcheting teeth on the driving rod 126. Each movementof the activating lever advances the driving rod forward, therebyadvancing the implant coupler 140 and the implant 138. As the implant138 is advanced forward, the arms 152A, 152B are forced apart therebydistracting the vertebrae 180A, 180B. The user then continues to advancethe implant forward and the implant enters the intervertebral space.

Multiple elements may be combined in the devices contemplated herein. Avariety of methods are also contemplated. One method includes a methodof inserting a spinal implant between two vertebrae, comprising: (a)placing an intervertebral implant between a pair of opposing arms of avertebral distractor-inserter, the distractor-inserted comprising: (i)the pair of opposing arms, having distal ends; (ii) a driving rodextending between the pair of opposing arms, wherein the driving rodcomprises an axis and a surface with a plurality of angled ratchet teethon at least a portion of the surface; and (iii) a drive mechanism inmechanical communication with the driving rod; (b) inserting said distalends of the pair of opposing arms between a pair of vertebrae from aposterior angle; and (c) actuating said distractor-inserter, therebydistracting said vertebrae and inserting said implant between saidvertebrae. In some embodiments, the method further provides for a devicewherein the driving rod comprises an axis and a surface having aplurality of angled ratchet teeth on at least a portion of the surface.The method can further comprise a ratchet drive mechanism incommunication with the angled ratchet teeth. Alternatively, the methodcan comprise the use of a device comprising a screw drive mechanism. Thedevice can be introduced between the pair of vertebrae from a posteriorangle, where the posterior angle is generally parallel to the axialplane and sagittal plane. In some embodiments of the method, the devicecan be introduced between the pair of vertebrae from a posterior anglewhere the posterior angle is substantially parallel to the axial planebut deviates about 20 to about 60 degrees with respect to the sagittalplane. The method further comprises the use of a distractor-inserter forinserting a spinal implant between the vertebrae. In some embodiments,the implant has laterally opposing walls that are substantially parallelto the axis of insertion. The method can further comprise inserting atleast two implants into the intervertebral space. One implant can beinserted on one side of the spinous process and another implant can beinserted on the other side of the spinous process. In some embodiments,the implant has laterally opposing walls that are substantially curved.In some embodiments of the method, one of the opposing walls issubstantially parallel to the axis of insertion and the other opposingwall is substantially curved. In some embodiments of the method, theactuating step can further comprise inserting an implant havinglaterally opposing walls in the intervertebral space wherein theinserting of the implant comprises repositioning the implant in theintervertebral space by following the curvature of the implant. Themethod can further comprise the use of a distractor-inserter in whichthe distractor-inserter comprises a housing in mechanical communicationwith the pair of opposing arms, wherein the driving rod extends throughat least a portion of the housing. The distractor-inserter can comprisea handle attached to the housing. Additionally, the method for insertinga spinal implant between two vertebrae can comprise the use of a ratchetdrive mechanism, wherein the ratchet drive mechanism of thedistractor-inserter comprises: (a) an activating lever mounted to thehousing by an activating lever pivot; (b) a first ratchet pawl coupledto the activating lever and adapted to engage the ratchet teeth and movethe driving rod distally relative to the housing; and (c) a secondratchet pawl adapted to engage the ratchet teeth and oppose proximalmotion of the driving rod relative to the housing. Furthermore, themethod can comprise the use of a distractor-inserter can comprise ahandle attached to the housing and the ratchet drive mechanism comprisesan activating lever spring coupled to the activating lever and thehandle, wherein the activating lever spring opposes proximal movement ofthe lever relative to the handle. In some embodiments of the method, theratchet-drive mechanism comprises: (a) a first pawl spring that opposesdownward movement of the first pawl; and (b) a second pawl spring thatopposes downward movement of the second pawl. The surface of the drivingrod comprises an area that is substantially free of ratchet teeth on acontiguous longitudinal surface of the driving rod, and wherein thedriving rod is movable proximally relative to the housing upon rotationof the rod about its axis such that the ratchet pawls are in contactwith the contiguous longitudinal surface that is free of ratchet teeth.The ratchet teeth can disengage from the first and second ratchet pawlsupon rotation of the driving rod about its axis.

Additionally provided herein is a method of inserting a spinal implantbetween two vertebrae, comprising: (a) placing an intervertebral implantbetween a pair of opposing arms of a vertebral distractor-inserter, thedistractor-inserted comprising: (i) a pair of opposing arms havingdistal ends; (ii) a housing in mechanical communication with the pair ofopposing arms and rotatable about an axis extending between the opposingarms; and (iii) a driving rod extending through at least a portion ofthe housing and between the pair of opposing arms; (b) inserting saiddistal ends of the pair of opposing arms between a pair of vertebraefrom a posterior angle; and (c) actuating said distractor-inserter,thereby distracting said vertebrae and inserting said implant betweensaid vertebrae. The method can further provide for the use of adistractor-inserter wherein the driving rod comprises a distal endhaving an implant interface, wherein the housing and at least a portionof the driving rod are rotatable relative to the pair of opposing armsand the implant interface. The implant interface can additionallycomprises an interface rotation element, whereby the interface rotationelement allows rod rotation relative to the pair of opposing arms. Thehousing can comprises a housing rotation element, whereby the housingrotation element allows housing and rod rotation relative to the pair ofopposing arms. In some embodiments, the distractor-inserter is adaptedfor single-handed use. The method can further provide for a device thatcan be introduced between the pair of vertebrae from a posterior angle,where the posterior angle is generally parallel to the axial plane andsagittal plane. In some embodiments of the method, the device can beintroduced between the pair of vertebrae from a posterior angle wherethe posterior angle is substantially parallel with respect to the axialplane but deviates about 20 to about 60 degrees with respect to thesagittal plane. The method further comprises the use of adistractor-inserter for inserting a spinal implant between thevertebrae. In some embodiments, the implant has laterally opposing wallsthat are substantially parallel to the axis of insertion. The method canfurther comprise inserting at least two implants into the intervertebralspace. One implant can be inserted on one side of the spinous processand another implant can be inserted on the other side of the spinousprocess. In some embodiments of the method, the implant has laterallyopposing walls that are substantially curved. In some embodiments, oneof the opposing walls is substantially parallel to the axis of insertionand the other opposing wall is substantially curved. In some embodimentsof the method, the actuating step can further comprise inserting animplant having laterally opposing walls in the intervertebral spacewherein the inserting of the implant comprises repositioning the implantin the intervertebral space by following the curvature of the implant.

Further provided herein is a method of inserting an implant betweenvertebrae, comprising: (a) placing a vertebral implant between a pair ofopposing arms of a vertebral distractor-inserter, saiddistractor-inserter comprising: (i) a housing; (ii) a pair of opposingarms in mechanical communication with the housing; (iii) a driving rodextending through at least a portion of the housing and between the pairof opposing arms; and (iv) a drive mechanism in mechanical communicationwith the driving rod, wherein the drive mechanism is adapted to move thedriving rod distally relative to the housing, and wherein thedistractor-inserter is adapted for single-handed distraction ofvertebrae and insertion of a vertebral implant; (b) inserting saiddistal ends of the pair of opposing arms between a pair of vertebraefrom a posterior angle; and actuating said distractor-inserter, therebydistracting said vertebrae and inserting said implant between saidvertebrae. The method can further provide for a device that can beintroduced between the pair of vertebrae from a posterior angle, wherethe posterior angle is generally parallel to the axial plane andsagittal plane. In some embodiments of the method, the device can beintroduced between the pair of vertebrae from a posterior angle wherethe device is introduced at a posterior angle that is substantiallyparallel to the axial plane but which deviates about 20 to about 60degrees with respect to the sagittal plane. The method further comprisesthe use of a distractor-inserter for inserting a spinal implant betweenthe vertebrae. In some embodiments, the implant has laterally opposingwalls that are substantially parallel to the axis of insertion. Themethod can further comprise inserting at least two implants into theintervertebral space. One implant can be inserted on one side of thespinous process and another implant can be inserted on the other side ofthe spinous process. In some embodiments, the implant has laterallyopposing walls that are substantially curved. In some embodiments, oneof the opposing walls is substantially parallel to the axis of insertionand the other opposing wall is substantially curved. In some embodimentsof the method, the actuating step can further comprise inserting animplant having laterally opposing walls in the intervertebral spacewherein the inserting of the implant comprises repositioning the implantin the intervertebral space by following the curvature of the implant.

Another method provided herein is a method for distracting adjacentvertebrae and inserting an implant between the distracted vertebrae froma posterior angle, comprising: (a) mounting the implant to a driving rodof a vertebral distractor-inserter having a pair of opposing arms, adistal end, and a drive mechanism in mechanical communication with thedriving rod, wherein the driving rod extends between the pair ofopposing arms; (b) positioning the distal end of the pair of armsbetween the vertebrae from a posterior angle; (c) distracting thevertebrae by single-handed operation of the vertebraldistractor-inserter; (d) inserting the implant between the distractedvertebrae by single-handed operation of the vertebraldistractor-inserter; and (e) retracting the pair of opposing arms frombetween the vertebrae. The distracting step can further compriseactivating the drive mechanism using one hand, wherein the activatingmoves the implant distally and distracts the pair of opposing arms. Insome embodiments of the method, the vertebral distractor-inserter has ahousing in mechanical communication with the pair of opposing arms,wherein the driving rod extends through at least a portion of thehousing. Additionally, the inserting step of the method for distractingadjacent vertebrae can further comprise advancing the implant into thedistracted space between the vertebrae. The advancing step can compriseactivating the drive mechanism using one hand and extending the implantbeyond the distal end of the pair of opposing arms. In some embodiments,the method further comprises the additional step of releasing theimplant from the distractor-inserter. The method provided can includethe use of a distractor-inserter comprising a the pair of opposing armscomprising a depth guard, and wherein the positioning step comprisesurging the pair of arms between the vertebrae up to the position wherethe depth guard contacts the vertebrae. In some embodiments of themethod, the vertebral distractor-inserter has a housing in mechanicalcommunication with the pair of opposing arms, wherein the driving rodextends through at least a portion of the housing, and wherein theactivating the drive mechanism comprises the step of ratcheting thedriving rod distally, wherein the driving rod comprises: (a) an axis and(b) a surface with a plurality of angled ratchet teeth on at least aportion of the surface, and wherein the drive mechanism comprises: (i)an activating lever capable of movement between a first position and asecond position and mounted to the housing by an activating lever pivot,(ii) a first ratchet pawl coupled to the activating lever and adapted toengage the ratchet teeth and move the driving rod distally relative tothe housing, and (iii) a second ratchet pawl adapted to engage theratchet teeth and oppose proximal motion of the driving rod relative tothe housing. The method can further provide for a device that can beintroduced between the pair of vertebrae from a posterior angle, wherethe posterior angle is generally parallel to the axial and sagittalplane. In some embodiments of the method, the device can be introducedbetween the pair of vertebrae from a posterior angle where the posteriorangle is substantially parallel to the axial plane but deviates about 20to about 60 degrees with respect to the sagittal plane. The methodfurther comprises the use of a distractor-inserter for inserting aspinal implant between the vertebrae. In some embodiments, the implanthas laterally opposing walls that are substantially parallel to the axisof insertion. The method can further comprise inserting at least twoimplants into the intervertebral space. One implant can be inserted onone side of the spinous process and another implant can be inserted onthe other side of the spinous process. In some embodiments, the implanthas laterally opposing walls that are substantially curved. In someembodiments, one of the opposing walls is substantially parallel to theaxis of insertion and the other opposing wall is substantially curved.In some embodiments of the method, the actuating step can furthercomprise inserting an implant having laterally opposing walls in theintervertebral space wherein the inserting of the implant comprisesrepositioning the implant in the intervertebral space by following thecurvature of the implant.

In some embodiments, further provided is a method for distractingadjacent vertebrae and inserting an implant between the distractedvertebrae from a posterior angle, comprising the steps of: (a) mountingthe implant to a driving rod of a vertebral distractor-inserter having apair of opposing arms, and a ratchet drive mechanism in mechanicalcommunication with the driving rod, wherein the driving rod extendsbetween the pair of opposing arms; (b) positioning the distal end of thepair of arms between the vertebrae from a posterior angle; (c)distracting the vertebrae, wherein the distracting comprises activatingthe ratchet drive mechanism; (d) inserting the implant between thedistracted vertebrae, wherein the inserting comprises advancing theimplant into the distracted space between the vertebrae, and wherein theadvancing comprises activating the ratchet drive mechanism; and (e)retracting the pair of opposing arms from between the vertebrae. Theactivating step can further comprise moving the implant distally anddistracting the pair of opposing arms. The step of activating theratchet drive mechanism, in some embodiments, can further comprise thestep of ratcheting the driving rod distally, wherein the driving rodcomprises: (a) an axis; and (b) a surface with a plurality of angledratchet teeth on at least a portion of the surface, and wherein theratchet drive mechanism comprises: (i) an activating lever capable ofmovement between a first position and a second position and mounted tothe housing by an activating lever pivot, (ii) a first ratchet pawlcoupled to the activating lever and adapted to engage the ratchet teethand move the driving rod distally relative to the housing, and (iii) asecond ratchet pawl adapted to engage the ratchet teeth and opposeproximal motion of the driving rod relative to the housing. The devicecan be introduced between the pair of vertebrae from a posterior angle,where the posterior angle is generally parallel to the axial andsagittal planes. In some embodiments of the method, the device can beintroduced between the pair of vertebrae from a posterior angle wherethe posterior angle is substantially parallel with respect to the axialplane but which deviates about 20 to about 60 degrees with respect tothe sagittal plane. The method further comprises the use of adistractor-inserter for inserting a spinal implant between thevertebrae. In some embodiments, the implant has laterally opposing wallsthat are substantially parallel to the axis of insertion. The method canfurther comprise inserting at least two implants into the intervertebralspace. One implant can be inserted on one side of the spinous processand another implant can be inserted on the other side of the spinousprocess. In some embodiments, the implant has laterally opposing wallsthat are substantially curved. In some embodiments, one of the opposingwalls is substantially parallel to the axis of insertion and the otheropposing wall is substantially curved. In some embodiments of themethod, the actuating step can further comprise inserting an implanthaving laterally opposing walls in the intervertebral space wherein theinserting of the implant comprises repositioning the implant in theintervertebral space by following the curvature of the implant.

Yet another embodiment of the method provided herein includes a methodfor distracting adjacent vertebrae and inserting an implant between thedistracted vertebrae from a posterior angle, comprising the steps of:(a) mounting the implant to a driving rod of a vertebraldistractor-inserter having: (i) a pair of opposing arms having a distalend, (ii) a housing in mechanical communication with the pair ofopposing arms which is rotatable about an axis extending between theopposing arms relative to the arms and to the implant, and (iii) a drivemechanism in mechanical communication with the driving rod, wherein thedriving rod extends through at least a portion of the housing andbetween the pair of opposing arms and wherein at least a portion of thedriving rod is rotatable about the axis extending between the opposingarms relative to the pair of opposing arms and to the implant; (b)positioning the distal end of the pair of arms between the vertebraefrom a posterior angle; (c) rotating the housing and at least a portionof the driving rod relative to the pair of opposing arms and to theimplant; (d) distracting the vertebrae; (e) inserting the implantbetween the distracted vertebrae; and (f) retracting the pair ofopposing arms from between the vertebrae. The distracting step canfurther comprise activating the drive mechanism, wherein the activatingmoves the implant distally and distracts the pair of opposing arms.Additionally, the inserting step of the method can further compriseadvancing the implant into the distracted space between the vertebrae.The device can be introduced between the pair of vertebrae from aposterior angle, where the posterior angle is generally parallel to theaxial plane and sagittal plane. In some embodiments of the method, thedevice can be introduced between the pair of vertebrae from a posteriorangle where the posterior angle is substantially parallel to the axialplane but deviates about 20 to about 60 degrees with respect to thesagittal plane. The method further comprises the use of adistractor-inserter for inserting a spinal implant between thevertebrae. In some embodiments, the implant has laterally opposing wallsthat are substantially parallel to the axis of insertion. The method canfurther comprise inserting at least two implants into the intervertebralspace. One implant can be inserted on one side of the spinous processand another implant can be inserted on the other side of the spinousprocess. In some embodiments, the implant has laterally opposing wallsthat are substantially curved. In some embodiments, one of the opposingwalls is substantially parallel to the axis of insertion and the otheropposing wall is substantially curved. In some embodiments of themethod, the actuating step can further comprise inserting an implanthaving laterally opposing walls in the intervertebral space wherein theinserting of the implant comprises repositioning the implant in theintervertebral space by following the curvature of the implant.

Another embodiment of the method provided herein comprises a method fordistracting adjacent vertebrae and inserting an implant between thedistracted vertebrae from a posterior angle, comprising the steps of:(a) mounting the implant to a driving rod of a vertebraldistractor-inserter having (i) a pair of opposing arms having a distalend and a depth guard, (ii) an implant depth adjustor that is adjustableto a plurality of implant depth settings, (iii) a housing in mechanicalcommunication with the pair of opposing arms, and (iv) a drive mechanismin mechanical communication with the driving rod, wherein the drivingrod extends through at least a portion of the housing and between thepair of opposing arms, wherein the mounting comprises the step ofadjusting the implant depth adjustor to control the maximum distalimplant depth achievable during the inserting step; (b) positioning thedistal end of the pair of arms between the vertebrae, wherein thepositioning comprises urging the pair of arms between the vertebrae upto the position where the depth guard contacts the vertebrae; (c)distracting the vertebrae; (d) inserting the implant between thedistracted vertebrae from a posterior angle; and (e) retracting the pairof opposing arms from between the vertebrae. The device can beintroduced between the pair of vertebrae from a posterior angle, wherethe posterior angle is generally parallel to the axial plane andsagittal plane. In some embodiments of the method, the device can beintroduced between the pair of vertebrae from a posterior angle wherethe posterior angle is substantially parallel to the axial plane butdeviates about 20 to about 60 degrees with respect to the sagittalplane. The method further comprises the use of a distractor-inserter forinserting a spinal implant between the vertebrae. In some embodiments,the implant has laterally opposing walls that are substantially parallelto the axis of insertion. The method can further comprise inserting atleast two implants into the intervertebral space. One implant can beinserted on one side of the spinous process and another implant can beinserted on the other side of the spinous process. In some embodiments,the implant has laterally opposing walls that are substantially curved.In some embodiments, one of the opposing walls is substantially parallelto the axis of insertion and the other opposing wall is substantiallycurved. In some embodiments of the method, the actuating step canfurther comprise inserting an implant having laterally opposing walls inthe intervertebral space wherein the inserting of the implant comprisesrepositioning the implant in the intervertebral space by following thecurvature of the implant.

Further provided herein is a method of implanting an implant in anintervertebral space comprising: (a) providing a distractor-insertercomprising (i) a pair of opposing arms, having distal ends; (ii) adriving rod extending between the pair of opposing arms; and (iii) adrive mechanism in mechanical communication with the driving rod; (b)inserting the distal end of the pair of arms between the vertebrae froma posterior angle; (c) actuating the distractor-inserter, therebydistracting said vertebrae and inserting said implant between saidvertebrae; and (d) repositioning said implant so that it occupies ananterior vertebral space. The method further comprises inserting animplant that has laterally opposing walls that are substantially curvedwith respect to the axis of insertion. The method can further comprisesa posterior angle, where the posterior angle is generally parallel tothe axial plane and sagittal plane. In some embodiments of the method,the device can be introduced between the pair of vertebrae from aposterior angle where the posterior angle is substantially parallel tothe axial plane but which deviates about 20 to about 60 degrees withrespect to the sagittal plane. The method further comprises the use of adistractor-inserter for inserting a spinal implant between thevertebrae.

Yet another method provided herein is a method of implanting implantsinto an intervertebral space comprising: (a) providing adistractor-inserter comprising (i) a pair of opposing arms, havingdistal ends; (ii) a driving rod extending between the pair of opposingarms; and (iii) a drive mechanism in mechanical communication with thedriving rod; (b) inserting the distal end of the pair of arms betweenthe vertebrae from a posterior angle; (c) actuating thedistractor-inserter, thereby distracting said vertebrae and insertingsaid implant between said vertebrae; and (d) repeating steps (a)-(c) onthe contralateral side of the spinous process. In some embodiments, theimplant has laterally opposing walls that are substantially parallel tothe axis of insertion. The implant can be boxed-shaped. The method canfurther comprise inserting at least two implants into the intervertebralspace. One implant can be inserted on one side of the spinous processand another implant can be inserted on the contralateral side of thespinous process. In some embodiments, the posterior angle issubstantially parallel to the axial plane and the sagittal plane. Insome embodiments of the method, the device can be introduced between thepair of vertebrae from a posterior angle where the posterior angle isparallel to the axial plane but which deviates about 20 to about 60degrees with respect to the sagittal plane.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

1. A method of inserting a spinal implant between two vertebrae,comprising: (a) placing an intervertebral implant between a pair ofopposing arms of a vertebral distractor-inserter, thedistractor-inserter comprising: (i) the pair of opposing arms, havingdistal ends; (ii) a driving rod extending between the pair of opposingarms, and (iii) a drive mechanism in mechanical communication with thedriving rod; (b) inserting said distal ends of the pair of opposing armsbetween a pair of vertebrae from a posterior angle; and (c) actuatingsaid distractor-inserter, thereby distracting said vertebrae andinserting said implant between said vertebrae.
 2. The method of claim 1,wherein the driving rod comprises an axis and a surface having aplurality of angled ratchet teeth on at least a portion of the surface.3. The method of claim 2, wherein the drive mechanism is a ratchet drivemechanism.
 4. The method of claim 1, wherein the drive mechanism is ascrew drive mechanism.
 5. The method of claim 1, wherein the posteriorangle is generally parallel to the axial plane and the sagittal plane.6. The method of claim 1, wherein the posterior angle deviates about 20to about 60 degrees with respect to the sagittal plane.
 7. The method ofclaim 1, wherein the implant has laterally opposing walls that aregenerally parallel to the axis of insertion.
 8. The method of claim 1,wherein the implant has laterally opposing walls that are generallycurved.
 9. The method of claim 1, wherein the distractor-insertercomprises a housing in mechanical communication with the pair ofopposing arms, wherein the driving rod extends through at least aportion of the housing.
 10. The method of claim 2, wherein thedistractor-inserter comprises a handle attached to the housing.
 11. Themethod of claim 2, wherein the ratchet drive mechanism of thedistractor-inserter comprises: (a) an activating lever mounted to thehousing by an activating lever pivot; (b) a first ratchet pawl coupledto the activating lever and adapted to engage the ratchet teeth and movethe driving rod distally relative to the housing; and (c) a secondratchet pawl adapted to engage the ratchet teeth and oppose proximalmotion of the driving rod relative to the housing.
 12. The method ofclaim 4, wherein the distractor-inserter comprises a handle attached tothe housing and the ratchet drive mechanism comprises an activatinglever spring coupled to the activating lever and the handle, wherein theactivating lever spring opposes proximal movement of the lever relativeto the handle.
 13. The method of claim 4, wherein the ratchet drivemechanism comprises: (a) a first pawl spring that opposes downwardmovement of the first pawl; and (b) a second pawl spring that opposesdownward movement of the second pawl.
 14. The method of claim 4, whereinthe surface of the driving rod comprises an area that is substantiallyfree of ratchet teeth on a contiguous longitudinal surface of thedriving rod, and wherein the driving rod is movable proximally relativeto the housing upon rotation of the rod about its axis such that theratchet pawls are in contact with the contiguous longitudinal surfacethat is free of ratchet teeth.
 15. The method of claim 7, wherein theratchet teeth disengage from the first and second ratchet pawls uponrotation of the driving rod about its axis.
 16. A method of inserting aspinal implant between two vertebrae, comprising: (a) placing anintervertebral implant between a pair of opposing arms of a vertebraldistractor-inserter, the distractor-inserted comprising: (i) a pair ofopposing arms having distal ends; (ii) a housing in mechanicalcommunication with the pair of opposing arms and rotatable about an axisextending between the opposing arms; and (iii) a driving rod extendingthrough at least a portion of the housing and between the pair ofopposing arms; (b) inserting said distal ends of the pair of opposingarms between a pair of vertebrae from a posterior angle; and (c)actuating said distractor-inserter, thereby distracting said vertebraeand inserting said implant between said vertebrae.
 17. The method ofclaim 16, wherein the driving rod comprises a distal end having animplant interface, wherein the housing and at least a portion of thedriving rod are rotatable relative to the pair of opposing arms and theimplant interface.
 18. The method of claim 17, wherein the implantinterface comprises an interface rotation element, whereby the interfacerotation element allows rod rotation relative to the pair of opposingarms.
 19. The method of claim 18, wherein the housing comprises ahousing rotation element, whereby the housing rotation element allowshousing and rod rotation relative to the pair of opposing arms.
 20. Themethod of claim 16, wherein the distractor-inserter is adapted forsingle-handed use.
 21. The method of claim 16, wherein the posteriorangle is generally parallel to the axial plane and the sagittal plane.22. The method of claim 16, wherein the posterior angle deviates about20 to about 60 degrees with respect to the sagittal plane.
 23. Themethod of claim 16, wherein the implant has laterally opposing wallsthat are generally parallel to the axis of insertion.
 24. The method ofclaim 16, wherein the implant has laterally opposing walls that aregenerally curved.
 25. A method of inserting an implant betweenvertebrae, comprising: (a) placing a vertebral implant between a pair ofopposing arms of a vertebral distractor-inserter, saiddistractor-inserter comprising: (i) a housing; (ii) a pair of opposingarms in mechanical communication with the housing; (iii) a driving rodextending through at least a portion of the housing and between the pairof opposing arms; and (iv) a drive mechanism in mechanical communicationwith the driving rod, wherein the drive mechanism is adapted to move thedriving rod distally relative to the housing, and wherein thedistractor-inserter is adapted for single-handed distraction ofvertebrae and insertion of a vertebral implant; (b) inserting saiddistal ends of the pair of opposing arms between a pair of vertebraefrom a posterior angle; and (c) actuating said distractor-inserter,thereby distracting said vertebrae and inserting said implant betweensaid vertebrae.
 26. The method of claim 25, wherein the posterior angleis generally parallel to the axial plane and the sagittal plane.
 27. Themethod of claim 25, wherein the posterior angle deviates about 20 toabout 60 degrees with respect to the sagittal plane.
 28. The method ofclaim 25, wherein the implant has laterally opposing walls that aregenerally parallel to the axis of insertion.
 29. The method of claim 25,wherein the implant has laterally opposing walls that are generallycurved.
 30. A method for distracting adjacent vertebrae and inserting animplant between the distracted vertebrae from a posterior angle,comprising: (a) mounting the implant to a driving rod of a vertebraldistractor-inserter having a pair of opposing arms, a distal end, and adrive mechanism in mechanical communication with the driving rod,wherein the driving rod extends between the pair of opposing arms; (b)positioning the distal end of the pair of arms between the vertebraefrom a posterior angle; (c) distracting the vertebrae by single-handedoperation of the vertebral distractor-inserter; (d) inserting theimplant between the distracted vertebrae by single-handed operation ofthe vertebral distractor-inserter; and (e) retracting the pair ofopposing arms from between the vertebrae.
 31. The method of claim 30,wherein the distracting comprises activating the drive mechanism usingone hand, wherein the activating moves the implant distally anddistracts the pair of opposing arms.
 32. The of claim 30, wherein thevertebral distractor-inserter has a housing in mechanical communicationwith the pair of opposing arms, wherein the driving rod extends throughat least a portion of the housing.
 33. The method of claim 30, whereinthe inserting comprises advancing the implant into the distracted spacebetween the vertebrae.
 34. The method of claim 30, and wherein theadvancing comprises activating the drive mechanism using one hand andextending the implant beyond the distal end of the pair of opposingarms.
 35. The method of claim 30, comprising the additional step ofreleasing the implant from the distractor-inserter.
 36. The method ofclaim 30, wherein the pair of opposing arms comprises a depth guard, andwherein the positioning comprises urging the pair of arms between thevertebrae up to the position where the depth guard contacts thevertebrae.
 37. The method of claim 30, wherein the vertebraldistractor-inserter has a housing in mechanical communication with thepair of opposing arms, wherein the driving rod extends through at leasta portion of the housing, and wherein the activating the drive mechanismcomprises the step of ratcheting the driving rod distally, wherein thedriving rod comprises: (a) an axis and (b) a surface with a plurality ofangled ratchet teeth on at least a portion of the surface, and whereinthe drive mechanism comprises: (i) an activating lever capable ofmovement between a first position and a second position and mounted tothe housing by an activating lever pivot, (ii) a first ratchet pawlcoupled to the activating lever and adapted to engage the ratchet teethand move the driving rod distally relative to the housing, and (iii) asecond ratchet pawl adapted to engage the ratchet teeth and opposeproximal motion of the driving rod relative to the housing.
 38. Themethod of claim 30, wherein the posterior angle is generally parallel tothe axial plane and the sagittal plane.
 39. The method of claim 30,wherein the posterior angle deviates about 20 to about 60 degrees withrespect to the sagittal plane.
 40. The method of claim 30, wherein theimplant has laterally opposing walls that are generally parallel to theaxis of insertion.
 41. The method of claim 30, wherein the implant haslaterally opposing walls that are generally curved.
 42. A method fordistracting adjacent vertebrae and inserting an implant between thedistracted vertebrae from a posterior angle, comprising the steps of:(a) mounting the implant to a driving rod of a vertebraldistractor-inserter having a pair of opposing arms, and a ratchet drivemechanism in mechanical communication with the driving rod, wherein thedriving rod extends between the pair of opposing arms; (b) positioningthe distal end of the pair of arms between the vertebrae from aposterior angle; (c) distracting the vertebrae, wherein the distractingcomprises activating the ratchet drive mechanism; (d) inserting theimplant between the distracted vertebrae, wherein the insertingcomprises advancing the implant into the distracted space between thevertebrae, and wherein the advancing comprises activating the ratchetdrive mechanism; and (e) retracting the pair of opposing arms frombetween the vertebrae.
 43. The method of claim 42, wherein theactivating moves the implant distally and distracts the pair of opposingarms.
 44. The method of claim 43, wherein the activating the ratchetdrive mechanism comprises the step of ratcheting the driving roddistally, wherein the driving rod comprises: (a) an axis; and (b) asurface with a plurality of angled ratchet teeth on at least a portionof the surface, and wherein the ratchet drive mechanism comprises: (i)an activating lever capable of movement between a first position and asecond position and mounted to the housing by an activating lever pivot,(ii) a first ratchet pawl coupled to the activating lever and adapted toengage the ratchet teeth and move the driving rod distally relative tothe housing, and (iii) a second ratchet pawl adapted to engage theratchet teeth and oppose proximal motion of the driving rod relative tothe housing.
 45. The method of claim 42, wherein the posterior angle isgenerally parallel to the axial plane and the sagittal plane.
 46. Themethod of claim 42, wherein the posterior angle deviate about 20 toabout 60 degrees with respect to the sagittal plane.
 47. The method ofclaim 42, wherein the implant has laterally opposing walls that aregenerally parallel to the axis of insertion.
 48. The method of claim 42,wherein the implant has laterally opposing walls that are generallycurved.
 49. A method for distracting adjacent vertebrae and inserting animplant between the distracted vertebrae from a posterior angle,comprising the steps of: (a) mounting the implant to a driving rod of avertebral distractor-inserter having: (i) a pair of opposing arms havinga distal end, (ii) a housing in mechanical communication with the pairof opposing arms which is rotatable about an axis extending between theopposing arms relative to the arms and to the implant, and (iii) a drivemechanism in mechanical communication with the driving rod, wherein thedriving rod extends through at least a portion of the housing andbetween the pair of opposing arms and wherein at least a portion of thedriving rod is rotatable about the axis extending between the opposingarms relative to the pair of opposing arms and to the implant; (b)positioning the distal end of the pair of arms between the vertebraefrom a posterior angle; (c) rotating the housing and at least a portionof the driving rod relative to the pair of opposing arms and to theimplant; (d) distracting the vertebrae; (e) inserting the implantbetween the distracted vertebrae; and (f) retracting the pair ofopposing arms from between the vertebrae.
 50. The method of claim 49,wherein the distracting comprises activating the drive mechanism,wherein the activating moves the implant distally and distracts the pairof opposing arms.
 51. The method of claim 49, wherein the insertingcomprises advancing the implant into the distracted space between thevertebrae.
 52. The method of claim 49, wherein the posterior angle isgenerally parallel to the axial plane and the sagittal plane.
 53. Themethod of claim 49, wherein the posterior angle deviates about 20 toabout 60 degrees with respect to the sagittal plane.
 54. The method ofclaim 49, wherein the implant has laterally opposing walls that aregenerally parallel to the axis of insertion.
 55. The method of claim 49,wherein the implant has laterally opposing walls that are generallycurved.
 56. A method for distracting adjacent vertebrae and inserting animplant between the distracted vertebrae from a posterior angle,comprising the steps of: (a) mounting the implant to a driving rod of avertebral distractor-inserter having (i) a pair of opposing arms havinga distal end and a depth guard, (ii) an implant depth adjustor that isadjustable to a plurality of implant depth settings, (iii) a housing inmechanical communication with the pair of opposing arms, and (iv) adrive mechanism in mechanical communication with the driving rod,wherein the driving rod extends through at least a portion of thehousing and between the pair of opposing arms wherein the mountingcomprises the step of adjusting the implant depth adjustor to controlthe maximum distal implant depth achievable during the inserting step;(b) positioning the distal end of the pair of arms between thevertebrae, wherein the positioning comprises urging the pair of armsbetween the vertebrae up to the position where the depth guard contactsthe vertebrae. (c) distracting the vertebrae; (d) inserting the implantbetween the distracted vertebrae from a posterior angle; and (e)retracting the pair of opposing arms from between the vertebrae.
 57. Themethod of claim 56, wherein the posterior angle is generally parallel tothe axial plane and the sagittal plane.
 58. The method of claim 56,wherein the posterior angle deviates about 20 to about 60 degrees withrespect to the sagittal plane.
 59. The method of claim 56, wherein theimplant has laterally opposing walls that are generally parallel to theaxis of insertion.
 60. The method of claim 56, wherein the implant haslaterally opposing walls that are generally curved.
 61. A method ofimplanting an implant in an intervertebral space comprising: (a)providing a distractor-inserter comprising (i) a pair of opposing arms,having distal ends; (ii) a driving rod extending between the pair ofopposing arms; and (iii) a drive mechanism in mechanical communicationwith the driving rod; (b) inserting the distal end of the pair of armsbetween the vertebrae from a posterior angle; (c) actuating thedistractor-inserter, thereby distracting said vertebrae and insertingsaid implant between said vertebrae; and (d) repositioning said implantso that it occupies an anterior vertebral space.
 62. The method of claim61, wherein the posterior angle is generally parallel to the axial planeand the sagittal plane.
 63. The method of claim 61, wherein theposterior angle deviates about 20 to about 60 degrees with respect tothe sagittal plane.
 64. The method of claim 61, wherein the implant haslaterally opposing walls that are generally curved.
 65. A method ofimplanting implants into an intervertebral space comprising: (a)providing a distractor-inserter having a pair of opposing arms having(b) inserting the distal end of the pair of arms between the vertebraeat a posterior angle on a first side of a spinous process; (c)activating the distractor-inserter (d) repeating steps (a) through (c)on a second side of the spinous process.
 66. The method of claim 65wherein the implant is box-shaped.
 67. The method of claim 65, whereinthe posterior angle is generally parallel to the axial plane and thesagittal plane.
 68. The method of claim 65, wherein the posterior angledeviates about 20 to about 60 degrees with respect to the sagittalplane.
 69. The method of claim 65, wherein the implant has laterallyopposing walls that are generally parallel to the axis of insertion.